I live in Maine, which isn't exactly a cycling Mecca due to the long winter, mud, and bug seasons. Even still, there are TONS of used fixies on CL for pretty cheap. I hand built the two I ride all the time, but could have saved a lot of money if I'd bought one with the components on it already and swapped to a different frame.

Avoid the Wal-mart junk, it's too heavy and not built well. This is one of those areas that you want to start out right or you'll never stay with it. I understand it's cheap, but personally I think it's a waste of money, which makes it expensive.