I would say 8k plus for one with good history.. The prices seem to be creeping up at the moment for good ones. The biggest problem is rot, check the inner wings around where the strut meets the inner wing, have a good feel around the turret base for plates as when these rot they are plated as a quick fix and the rot will come back.

Mine went around the passenger side and I had the entire inner wing replaced for peace of mind. The other areas are sills and the rear box section under the rear floor.