I like the fact that Belize is still unchained in regard to Mickey D and the Starbucks goddess, among others. However, when traveling in the States, I will stop and get two $1 double cheeseburgers and a glass of water, because I can't imagine that they don't lose money off of me if I do that.
I don't think that anyone directly mentioned that there will usually be a 5% charge on the use of a credit card for merchandise or services and you can get a marginally better rate of exchange at any bank. The locals know that and that is why you are most likely to get change in Belizean currency.