If you are just there for a week or so, the cost of food from one store to another is not going to play a big part. Go to the closest and most convenient location. I beleive Market Garden at the bottom of Billy Folly Rd. offers a 5% discount if you check out prior to 8:00am. You might have to ask about it but I would go there versus running all over the island to save a few $$, IF you are saving any at all.