Charlie:
Hah, well you have a point there. I have a feeling it has more to do with saturation when it comes to Ag stuff, the more there is the less the demand will be for the used stuff. The mid-west just has more farm then the east does now. Other factors are the hard winters we have up here, the salt just eats the old stuff up so you pay more for the stuff that survived (that's applies more to cars & trucks but it effects everything after a while).
Dennis:
I know there's more money in the parts then there is in the complete tractor, but it seems (to me) that the used parts just are not fetching the (some time outrageous) prices they did a year or two ago. I have a grill housing (I'm not going to mention the model so I don't cross into "poof" territory) that just a year I know would have probably fetched double what it would today, then again that's using eBay has a barometer which I usually swear off doing.