Giant makes one called a Halfway that is about 450. Citizen Bikes make one for less than 200, but I don't know anything about the quality. Sunn makes a really basic one around 300. Most others like Bike Friday, Birdy, Brompton are even more expensive than the Dahons. You might check want ads, it seems people either love or hate folders, and you might get one cheap there. At the bottom end, Walmart carried one for a while, but I don't know if they still do.
I have heard only good things about Dahon, but have never personally owned one.