The K6 of Lenovo is great and not too expensive. Got one when I continued my contract with my mobile service provider, but I sold it almost immediately on ebay as I'm more of an iphone guy.

If you want a great phone for a low price however you should go to some pawnshop. Almost fresh out of the box flagship phones for ridiculously low prices are a common thing there. Of course I'd flash a new OS on such a phone, just in case it's stolen. Also you don't usually get a warranty.