Remember you can also buy wine, liquor, cigarettes etc at the arrival duty free in Belize. This is a totally separate duty free allowance that is in addition to your duty free allowance when leaving the USA.
Definitely the best idea. I mean you can get $7 U.S. bottles of wine and 1 liter Absoluts for around $20 U.S. If you have any specialty liquors you need to bring then bring it, but incoming duty free is a pretty good deal, especially if you're accustomed to Belize alcohol prices.