Being into vodka martinis, on the first trip down (not knowing what would be available, I had not yet found this board) I took a bottle of vermouth soaked olives, and picked up some vodka at the duty free in DFW (cost me the same as it would have in a liquor store at home). A pain in the butt. Second trip I took the olives and picked up the vodka at the grocery store at the north end. Cost me about 6 bucks more, but it lessened the hassle immensely. Thats what, the cost of 2 or 3 Belikins? My advice is, unless you are upper shelf brand specific, determine whether it is that important to you. My experience with the duty free has been pretty spotty on booze coming out of the states, and it is usually a lot cheaper at the duty free in the island airports when you are coming back.
You got Belikin, you got great rums, panty rippers, blue thingies, and a host of other island drinks, why bring your own?
Been there, done that, the washing machine ate the T-shirt