Curtis Nelson would be an ideal replacement. And we'd make a profit. We'd still need another late 20'2 central defender though. Bassong perhaps available after Norwich gained promotion?
I'd drive him there for that. Honestly. We have shown with Upson that we can get replacements for free.
Centre backs generally do not demand a large fee. Would be amazed if we got anything near that for Dunk, lets not forget the countless mistakes he made.