Very few places to shop on Bimini. There are 2 hardware stores - one at each end of N. Bimini, and several little general stores, an art gallery which never seems to be open and the outdoor market.
What to buy: Bimini Bread and Coconut Candy. The coconut rolls are too sweet for me. They also have T-shirts, straw baskets and souveniers, although there isn't much in the way of post cards, which are about the ugliest I've ever seen of a place with such special scenery.
What to pay: To a certain extent you can bargain.
Waiting room and ticket office
What to buy: Post cards of the airplanes. Possibly you can also get literature about the airline here.