Ox had his best season for us being he was sold too. Liverpool fans was unbelievably excited about him. Then he got injured, and injured and injured. It happens.
That said, there are clubs who also buy proven duds, hoping to resurrect them. And there are tons of success stories too for those. But generally those are bought at a bargain, and gambles on them are normally due to the fact they are cheap.
We helped Chelsea recoup all their money, and also apparently gave the player as good a contract or better than he had at Chelsea.