Just went here for the first time this week- and I must warn you- the restaurant is only open for…read morelunch, and only from June to September!
That said, the salads are EXCELLENT (my companion had the goat cheese salad which was both beautiful and delicious) and the burgers are not bad (this is coming from an american who lives in France and rarely has the opportunity to enjoy a good hamburger!)
Currently, you can expect to pay about 12 euros for that burger with fries and a small side salad, and between 12 - 15 euros for a salad main course.