Petit Casino has more, and more nice stuff, in it than most people would expect. And if you are buying french stuff (for example dijon mustard, or canned goods, or snacks, or wine, or cheese...) then I think the difference in price between Petit Casino and and the Super U in Marigot is miniscule. If, on the other hand, you go there looking for Bud Light, Doritos and Kellogs Corn Flakes, then you are going to believe that the place is exorbitantly expensive, as Petit Casino is supplied from the huge French grocery chain Casino, and they obviously don't have a good system to get American items to them for reasonable costs. So, give it a try. Also, try the rotisserie chicken from Yellow Sub - order in the morning, tell them when you will pick it up. Get the potatoes, for additional $, as they are basted in the chicken juices for hours ;-)