I'm arriving in St. Thomas late August 11 and staying over and checking in at the Westin Villas on August 12. I'd like to get some light groceries- beer, lunchmeat, water, snacks - for our stay. Is it better to buy in St. Thomas and take over on the ferry or are the prices pretty much the same in St. John? I have been reading that it's generally pricier in St. John but I'm not sure if I want to bring everything over on the ferry. Thanks!