Basically, the problem seems to be that the USA does not have "sterile transit"; if your plane stops there in the way to somewhere else, you have to disembark and go through customs, and you need an expensive visa.
It's not the money but the abuse they can dish out at you. Even if you get a visa (which is a pain in the neck and a total time sink on it's own), customs can just tell you "You know what? Go f yourself." After you've landed...