I humbly disagree. It GREATLY reduces waste and isnt much work at all to be honest. 6people on a 45' cat, worked great last week. Have done the big provision countless times, and this is honestly WAY easier and substantiallycheaper.

Anchorages with reasonably stocked markets:
Spanish Town - Riteway/Bobbys, Etc.
North Sound - BEYC & Leverick - walk from dock
Trellis - small market in bay, or taxi to East End Rite Way. (also can get delivery here) - walk from dock
Anegada - Market is good, but warm baked goods delivered in the morning is even better, ask the dude who collects trash and for the mooring. If you tie a dry bag to the stern, he will drop them in for you. walk from dock.
Jost - 2 great markets - walk from dock
Cane Garden Bay - lots of options - walk from dock

Thats an easy 2 day rotation and you spread your funds across a lot more than 2 large corporations.