Provisioning -vs- doing it ourselves
The best prices for provisioning in Tortola are at K Mark''s ( I know, I know ) and Rite Way. The Ample Hamper at Soper''s has some of the more exotic food i.e. European imports. We always do the provisioning ourselves and leave the extra booze and beer to the staff at Sunsail at the end of the trip.
If you go to St Thomas you will find even better prices.