FWIW I watched the following tractor sell on a local retirement auction in Sept of 2008, I don't think prices have went down since then on much of anything.

Deere 4455 tractor 2wd, One owner, 4457 hrs, 18.4x38 bias singles, 15 spd ps, 2 remotes, excellent cond $48,200

Here's a link to a thread with the sale results, the link to the sale bill is no longer usable.

http://talk.newagtalk.com/forums/thread-view.asp?tid=64206&posts=22&highlight=4455&highlightmode=1#M454876