this review is long overdue. i have been to Diamond 9 more than a handful of times and have never left disappointed. they really care about their customers, young and old. ive even been fortunate enough to witness them doing charitable work with non-customers as well. every single person i have had the pleasure to interact with there have been pleasant. including the sea of vendors that are there on wednesdays and saturdays. the pokemon selection is not immense that it becomes overwhelming, but definitely more than enough to warrant spending more than half an hour shopping. of course it helps that almost all their cards are priced at or sometimes even below market so obviously you want to buy all of them. to sum it up, Diamond 9 has all the makings of one of the best LCS in the area, and I feel lucky to have them so conveniently located near me. i will be coming to this shop for years to come. read more

First, I will list all the facts that I have experienced this past weekend (August 22, 2026 and August 23, 2026) at Diamond 9 Sports and the days leading up to the event. I will save my opinion at the end of what transpired. Timeline of Events Friday August 7th, 2026 Sign ups for One Piece Card Game 4th Anniversary Event (OP-17 Release Event) for Diamond 9 Sports: Saturday, OP17 Prerelease (Saturday August 22nd) & One Piece Card Game 4th Anniversary Event (OP-17 Release Event) for Diamond 9 Sports: Sunday, OP17 Prerelease (Sunday August 23rd) made available on the Bandai TCG Plus app. I successfully signed up for both events at $40 each Both events format is One Piece Card Game (English) - Sealed (Sealed format: 6 Packs (each participant should use the same number of packs.) After opening 6 packs, players build a 40-card deck, and a 10 DON!! card deck. (Source: https://en.onepiece-cardgame.com/pdf/tournament_rules_manual_op02.pdf ) Friday August 21, 2026 10:01 AM Received notification that the event has changed to Constructed format where there will only be 3 packs given out. The cost of the event remains $40. By this time all other events from other stores have filled up. Saturday August 22nd The event's format remained Constructed, however Entry was reduced to $10 and we received only 1 OP17 Booster Pack along with the promotional materials (OP17 Special Don!!, Rainbow Luffy + Luffy Promo, OP17 Release Stamped Promo Pack). Prizing (Gold Stamped Luffy) was given out to the winner. I paid this event in cash. Sunday August 23rd The event changed to Saturday's format: Constructed, Entry at $10 and we received only 1 OP17 Booster Pack along with the promotional materials (OP17 Special Don!!, Rainbow Luffy + Luffy Promo, OP17 Release Stamped Promo Pack). Prizing (Gold Stamped Luffy) was given out to the winner. I paid for this event with my credit card as proof of transaction. Opinion and Review I have been coming to Diamond 9 for a few months for their events. Thought their pricing was fair and the store owners were nice enough. That being said, how they handled this event felt very bait and switch. They advertised this event as $40 where you would get 6 booster packs. In the days leading up to the event the price and format changed (which went to $40 for 3 booster packs to $10 for 1 booster pack). This isn't an allocation issue. As Diamond 9 received their allocations of One Piece cards for this event. They just simply reduced the number of allocation of the booster packs to the players who signed up and kept the difference to sell at market rate. I agree that it is the store owner's right to change the price of a product when it fluctuates with the market but to change the format and the price after people sign up only to get notification of the format and price change the day before the event is simply bait and switch. I will not trust Diamond 9 for any business in the future as their pricing of events can change. read more

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I came to Diamond 9 for their Wednesday TCG and sports collectible show, which features many vendors. The vendors there are kind and welcoming. I saw some familiar faces, and met some new folks. Luckily, I came early enough to get good-valued cards while they were still unbought and left feeling very happy. The cards do have a wide range in price depending on the rarity and condition. Overall, I had a great expedience here. Whether you're looking for affordable cards or would like to stop by a card show on a weekday, I'd recommend coming here on a Wednesday (3-9pm). read more

Diamond 9 Sports - Hobby Shops Near Me - Placentia, California

Worst place ever I witnessed this owner be a complete as$&ol# to some people during a pin event this was a really bad experience. read more

Diamond 9 Sports - Don't go here - Hobby Shops Near Me - Placentia, California

I attended their OP17 prerelease event and the format changed after people had already signed up. Staff said they couldn't give out the originally expected packs because they'd "lose money" with market prices being higher, while the store was also selling OP17 at $17 a pack and $400 a box. The whole experience felt misleading and left a really bad impression. read more

Set up this past weekend at Diamond 9. It was great. Highly recommend their shows in Wednesday and Saturday. Lots of collectors and traffic. Had a fantastic time. Thanks to Robert and the team at Diamond 9. Well done!! read more

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Incredibly friendly knowledgeable and staff. They treated my kids with kindness and support. We just had a horrible experience at Anastasia Collectibles in Fullerton so this was a nice difference. Highly recommended. read more

Amazing shop I work at the coffe shop across the street I always like to go here during my breaks it is really fun to shop around and it's great to see this community coming together and the employees and owner are very nice but my only complaint is that they buy at 60 percent I sold them a few of my ir cards and a vintage card wicth was basically 70 dollars in value market at lease give me 70 percent went home feeling like I lost value especially at the price I bout the packs and also they close way to early I work the night shift so I don't always make it in time other than that amazing shop amazing employees would recommend for shopping but not for selling anyway thanks to dimond 9 i always have fun at my job read more

Good selection of old cards they better get some more because they will run out since I'm buying a few daily planning on investing 12k here before sept fast friendly service pat and rob are knowledgeable the wife of rob is cool just don't know here name worth a try they have a show wed and sat call for times read more

Always solid prices & service ! My go to for psa submissions & card browsing! Saturdays there are card shows , they have games playing on big screens & clean bathrooms! Solid prices on retail & extremely competitive pricing on hobby. read more

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Great people, something for everyone. I collect junk wax and there was quite a selection along with lots of modern as well. All the vendors are cool and share a passion for the hobby. Definitely recommend checking out Diamond 9! read more

Found this place, almost accidentally while shopping at Grocery Outlet, in the same parking center. I saw Cards and had to take a look. I was amazed how big their unit was.. my first thought, was how did they stay in business... Well it's been months since then, and I can genuinely say, they have a LEGIT, one-of-a-kind operation there! From their events, inventory, service... this place is a gem. The most impressive was their staff. The owner is super nice. I believe he was a math teacher, perhaps that is why he is so patient with noobs like me. But everytime I had questions, he's always answered them perfectly... Their manager Jada is amazing too, she's helped me the most so far as I've been trying to get some cards graded. She not only superbly skilled at rating cards, like the owner, she takes time to explain what she sees. Their expertise is hands down the best. But combine that with their down to earth welcoming service, these folks are ideal ambassadors to the card world. I had so many dumb questions, as I've been getting back into cards, but they've never made me feel like an idiot and have educated me with the grading process. The best VALUE EVER - they will look at up to 10 cards per day to see if they are worth submitting to PSA to get graded. If you do decide to get them graded, you can send with their cards and get their discount. Hands down best deal ever! Plus they unknowingly give us free lessons on how to rate our own cards lol jk. I'm sure they know but it's just a great deal read more

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Save yourself the frustration -- check prices before you buy anything here. My 80-year-old mother took my 10-year-old son here for his birthday and purchased a Topps 2026 Series 1, 14-pack box of baseball cards for $90. The same product is available at Best Buy right now for $49.99 with same-day pickup. That is an 80% upcharge on a standard retail item that anyone can buy today without leaving their couch. It's also worth noting that Diamond 9 Sports Cards is NOT an authorized Topps retailer. When I called to ask about the pricing, I was told they buy from resellers and don't accept returns. Fine. I called back and asked only if we could exchange it for something harder to find -- something that would actually justify the price of a specialty shop -- since what we bought is clearly available anywhere. The owner responded by telling me I was rude for calling it a rip-off, attempted to justify the price with a tax argument that doesn't hold up mathematically, and then hung up on me. Charging $90 for a $49.99 product is one thing. Refusing any resolution and hanging up on a customer asking a legitimate question is another. My son got his birthday gift, but my family will not be returning. If you're looking to buy Topps products, do yourself a favor and find an authorized Topps retailer -- you'll get a fair price and the peace of mind that comes with it. I'd encourage anyone -- especially seniors, parents, and grandparents shopping for kids -- to look up prices before making a purchase here. read more

I walk into the store with my 20 cards that I'm looking to make a few bucks on because I'm a kid. And I walk up to a guy to show him my cards and while he's checking my cards out the owner comes up to me and threatens me to leave his store saying you can either buy a table or you are getting kicked out. I said I'm only selling a few cards I'm not buying a table. He yells at me to get out and records me and gets in my face and starts threatening me. As a kid Im scared for my life that he's going to do something to me. He walks me out the store and continues to record me and follows me to my car. He records my license plate and yells at me to never come back. Sad how this place used to be lovely and fun to go to and now they don't care about anyone. PLEASE listen to me and don't go here, I can't believe how disrespected and low he made me feel. read more

Diamond 9 Sports - D9 - Hobby Shops Near Me - Placentia, California

Great card shop, staff is friendly and knowledgeable. Great selection of vintage and modern.

Went to my first op tounry here Staff looked out for us new comers amidst all the chaos. Really took care of us during op10 prerelease. wanna go to their locals but I have grad school on weds. My home boy picked up some j pokemon cards there for a good price too from what he said. Guy at the counter with the curly hair and glasses you the man read more

I've given this place numerous chances. but every visit has been a bad one. The owners are very rude and act like we are all a inconvenience with them. Not only do they give you attitude about what you collect or are looking for, but grunt every time you ask a question. I've submitted things to them so we can get something graded with PSA, but always comes back at a lower grade. I guess poor mishandling on their end. Plus the floors are always sticky and dirty and makes the place feel so unsanitary and poorly maintained. It's disappointing because it's a good spot, but the attitude ruin it. There are other spots around there that are way better and treat you how you want to be. (Just look at the Yelp comments he leaves). Sadly, my son and i will not be back. read more

Nice place and nice shows on Wednesday and Saturday. Good table prices and table amount.

Could have been a good one but sadly these guys are very unprofessional. There was a lot of people that used to love this spot until almost all the really good old vendors stopped coming. Owner Rob amd his children are very rude and a bunch of SCAMMERS! PLEASE DO NOT TRUST THESE PEOPLE! Try it and see for yourself. Dont say you weren't warned! They were good in the beginning til theyre not and start showing their TRUE COLORS. They think everyone is just like them scamming people. Going around, making trades, meeting other collecters like ourselfves seem to be a BIG PROBLEM unless you pay for a table. But what if youre barely starting this business and hardly have any cards to push?! They still want you to get a table even if it means only having 5-6 pcs of cards to sell. I know business is business but GOD DAMN can you cut newbies like myself a slack?! After telling them I was new and barely starting Rob and one of his sons screams at me saying im making deals and need to pay for a table if I want to continue. It's a really sad, dishonest, uncomfortable environment to be in. This hobby is supposed to be fun! You guys are the epitome of "MONEY HUNGRY, UNPROFESSIONAL business establishment." Good luck, Rob! Maybe you should start learning how to be a good sample to your children and other people. BE NICE! BE HUMBLE! BE HONEST! BE PROFESSIONAL! read more

Came here on a rainy Tuesday afternoon just as I was passing by. After 15 years, I recently got back into sports cards and didn't want to walk in when they had their show since it's been a while. The man helping me was very chill and relaxed and you can tell he really enjoyed the trading card culture and wanted to help preserve what it's all about. I got 3 psa slabs and '87 baseball pack. He took me over to his personal booth and let me take a few cards for free. This place definitely made me feel like I was a kid again looking for cards that I'm interested in, and not cards that a seller is trying to make money on me for. Great experience. read more

Great selection and helpful employees! My son is a very new collector and plenty of folks have taken time to walk him through the best cards for his budget. read more

There card show is pretty cool.to.buy and sell cards. Its every wesday and Saturday. Wensday is better. Staff is cool and friendly

I love this place! The owner is super cool and will give you honest feedback about psa submissions.

This store and its staff are so great. I needed to make goodie bags for my son's baseball team and Amazon sent me half the packs of cards I expected and I was a little panicked when I rolled in. The store owner offered to make me the other packs for free if he could add their business card to them. Ummm- yes please! He ended up giving me enough packs for my whole team plus extras and they were a huge hit. I am now a loyal customer and fan of this store forever! read more

Diamond 9 Sports - Baseball card packs made for my son's baseball team- huge hit! - Hobby Shops Near Me - Placentia, California

Came by for their Wednesday show event. About 20 dealers had their own tables setup, and Diamond9s own section for their business. Most of the vendors were friendly, and easy to talk to. Yes they are resellers, but that is part of the hobby. Shop around to find better prices or even negotiate. I'm giving them 5 stars simply because the owner was friendly and seems to care about this hobby. I brought my boy to his first card store because he's beginning to be interested in the hobby. The hardest part is feeling comfortable in a new store, new hobby. Well, they made my kid giddy with joy with some free basketball cards to help with some collection, as well as he was able to buy an older card for a fair price. It's the memory of him buying his own card, one that he likes, plus how the owner treated the exchange is what makes the experience 5. (I've been to stores in the past where no one even acknowledges you). Prices are relatively market price, saves me a trip from driving around looking for something sold out. Will come back again to shop around. read more

I went here a month ago and honestly such a good experience!! I'm recently getting back into pokemon collecting and the people here are so nice! I'm currently gonna go back today haha. :) read more

My son and I really enjoy coming here. I like to use this shop to send our cards to PSA. One of the best times we have is when we go on Saturdays and check out all the vendors in the shop! A great wide variety of vendors that have all sports cards and memorabilia. read more

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Cool spot but it's definitely lost its spark lately. It's mostly TCG vendors now and not so much sports. I know it's a business so whatever makes money, makes sense. read more

First time visit! I came here to show some cards and see what I can get for them. Spoke with the owner and he took the time to look through all of them and inspect the cards I wanted to possibly grade himself. He also took the time to explain grading and how the hobby works which was super nice because people are always trying to get one over if you have nice rare card and because I'm new. The offer great grading services where they drop off and pick up for you which relieves the scare of packages getting lost in transit. 10/10 will be back for showcase nights and to talk nba cards. Thanks again guys ! read more

I'm just gonna flat out say it, the owner, rob is horrible. I just got kicked out of the show for doing a table and not having a parent. My dad came and asked for a refund and they tried to tell us that we didn't pay. They told us to leave in 20 minutes if there was no parent and so we kept going. Rob came up and said we had to leave after 3 minutes. My friends I have been selling their for three years without parents. We have done 40 shows and have never had this happen. Rob called my dad a bad parent for leaving my friend and I there. We are 15 years old and are more than capable of not having anything happen to us. Warning Rob said it is unsafe for kids to go there so do not let your children under 18 go if you don't have a parent, I will never be going there again. Good luck, Rob. read more

This place low balls me every time I go in with premium cards and they just keep lowball me over and over and over

Great store, Rob and Krista are awesome! Both new product and vintage and good prices.

Got a table for the Wednesday show, on Sunday afternoon. Sunday night, came down with severe sinus infection. Tried calling twice with no answer both Tuesday afternoon and Wednesday. After no answer on Wednesday I drove down there. They said they'd call me back. They didn't call me back. I got out of bed cuz I don't like to not be a man of my word, I went to go speak with the owner. Owner with a smile on his face looked at me and said sorry if it's not 24 hours in advance there are no refunds or exchanges.. i took 3 days off work only for the owner to say their policy is more important than my business. Understood. Will go elsewhere read more

About a year ago I came across a bunch of old childhood sports and Pokemon cards. I was unsure of their value and decided to bring them to Diamond 9 for appraisal. I had no idea of the value of many of the cards and was unsure of what PSA was or CGC etc. The owner of Diamond 9 could have robbed me blind considering one of the cards I had in my possession. It was a Paul Konerko 1998 SkyBox E-X2001 - Essential Credentials Future numbered 4 out of 10. I know for a fact he knew the value of the card and could have bought it off of me for super cheap because I was desperate at the time. He did not he instead told me to do my own research and that he was not interested in buying my cards. I ended up getting the card graded at Diamond 9 after a few weeks of research and it received a PSA8. I would go on to sell the card for $3,000. I highly recommend this store considering how honorable the owner is. read more

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It shows really poor consideration for your customers when you do not open when you say you will. I drove out of my way today to visit your store for the first time. I arrived at 5:45 knowing that you did not open until six so yes I expected to wait, but I waited until 630 and nobody ever opened the business. There were also no signs on the door or any information on their website indicating they might be closed today. Doubt I will be back after wasting my time and fuel today. read more

Love this shop. I've been going here since they opened. My 13 year old son sells cards here on some Saturdays and Wednesdays. The prices are fair and Robert is an honest guy who will give deals within reason. You can tell he loves card collecting and seeing his customers happy. He is also really patient with kids. If you have a card you want graded, he will give you his honest opinion, just don't get upset when he gives you his honest opinion. If you don't like his opinion, get it graded yourself. Dont come here and trash him for being honest. Aside from Robert, Krista is very friendly. Gavin is knowledgeable. And Chase, well, he does a good job of picking up sodas from grocery outlet and folding boxes! Kidding...he does other stuff and is helpful too. read more

When we come here every time it's the best! Employee's are always very nice big space for card shows and great card selection. I always recommend this place! read more

This shop is more than a sports card store. Wednesdays and Saturdays are Card Show days at Diamond 9 Sports in Placentia, CA. I've been to a few shows, and they are fun. The number of vendors varies from show to show, but it's always been a terrific time. If you are a card collector, then Diamond 9 shows are a good place to go. read more

Seems like an okay place but, I wouldn't go in expecting any great deals. To be fair I'm only collecting non-sports cards so I can't speak to their sports cards dealings. I dropped in since I was grabbing food nearby, but saw their sign and got an itch to get some packs to rip. Turns out it was their show day so there were a lot of people in there. I browsed for about 5 minutes and it didn't look all the vendors had shown up yet as there were many tables left. Anyway, got to looking at the sealed stuff and some of the gaming singles and wasn't impressed. They had a Crown Zenith ETB for 120 which, after tax is double the MSRP on a set still getting printed and widely available. I expect to pay higher than the MSRP at a brick and mortar but, not double. When I see the FLGS doing stuff like that I personally question the other prices. So I tend to agree with the other reviewer that complained about the prices. Maybe that was an individual vendor, I don't know. That said, there were quite a few people there so people must like the place. read more

There's only so much I can say about Diamond 9 Sports. In fact, I'll tell you. I live in LA but I drive about 2 hours to get to Diamond 9.... Why? Because they set the experience that customers can enjoy! They're very versatile who else has the capacity to be both an events center for the Hobby and a card-shop? Diamond 9!!! I've seen Diamond 9 grow through the couple of years I've known them and I'm very proud to endorse this! Rob and Krista are simply the best! They do their best to keep a SAFE, fun and POSITIVE environment. It was definitely my sanctuary and a great getaway when needed. They're very knowledgeable about their craft within the hobby space and are fair when it's time to deal with them. Thank you for helping me grow my platform in the hobby. I will never forget the both of you! read more

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