We indeed used the duty free when we came into Belize. We used it again when we left. We left quit a bit of money there actually.
I dont recall the number we were allowed to bring into Belize, but we did bring 4 and 2 cartons of cigarettes. The cigarettes were the cheapest anywhere!
I would suggest you bring some wine/liquor in if you plan on drinking a lot. We spent plenty on drinks at the restuarants and bars and cinsumed all we bought at duty free!
Damn I wish I had my ass in the sand and toes in the water with a panty ripper in my hot little hand.