Last minute charter in BVI''''s
The name of the place we used to provision was Bobby''s Marketplace http://www.bobbysmarketplace.com/ . We were a little reluctant to rely on them for all our provisions since it was our first time, but I was very happy with their service and would use them again. We too looked at the Sunsail provisioning service and were unimpressed. In general, I found most food items were quite a bit more expensive than US prices, I keep reading on the web about 15% over US prices, my experience was that its more like 50%+. There was a Store called "Ample Hamper" (I think) at the Sunsail base but their selection was much less complete than Bobby''s, but they did have the basics and you can''t beat the convenience. If you go to Bobby''s its a taxi to Roadtown($20 per person each way if I recall, adds up for a family of 4).
While we were happy with our Sunsail charter, I would look into using Moorings next time just for the convenience of being in the "big city" of Roadtown for provisioning.