Hands down this is the best site you can find to purchase rare or even common cichlids. He has just about any New World cichlid you could think of, and some wild caught. Even if you aren't looking to buy right now I suggest checking out the site to see some of these amazing fish.
I know you wanted cheap, but if you plan on a top of the line cichlid tank this is the way to go!
If you want cheap just go to a your LFS
and check out what they have. I guarantee they will never look this good.