Keep in mind that Ambergris Caye is, with the better sections of Belize City, the most expensive place to live in Belize. Housing prices are at or equal to those in Florida, and some are above those in Florida. There are a number of places in Belize where you could live for one-third or one-half of what it costs in San Pedro.
Having said that, when I was researching my latest book on Belize (Adapter Kit: Belize) being publishing in early August by Avalon, the Moon Handbook folks, a number of expats told me they were able to live on Ambergris Caye for a good bit less than back home in the States. This, they said, was because they had a fairly simple lifestyle and didn't need a lot of luxuries. Also, in San Pedro certain things don't cost much -- for example, you don't need a car or gas or insurance, and you don't need a furnace or furnace oil. You don't need a lot of fancy clothes, routine medical care is moderately priced, property taxes are low, etc. But things like apartment rents, groceries, electricity and water are MORE expensive than in many U.S. towns.
Belizeans are pretty accepting, and they tend to take people one at a time, but frankly no matter where in Belize you live unless you are an exceptional person it's unlikely you are ever going to totally fit in. I think that is true in most places in the world, even to some degree in the U.S. One is molded by one's experiences growing up, and it is difficult to adust totally to a new culture, even if on the surface that culture isn't too different. Many expats in Belize seem to live in a kind of cocoon with only superficial contact with non-expats. Nothing wrong with that, I guess, as that happens in St. Petersburg, Fla., too.
There's a long chapter on living in San Pedro in my forthcoming book.
Belize First http://www.belizefirst.com/