After reading your querrie, I opened our greater area ( No. CA) Craigslist to see what is currently what. No surprise, HD, diesel/4x4 pickups from ANY mfgr. with ANY amount of miles on them are demanding much higher prices than their petrol powered sisters. The only soft area seemed to be any Ford/International diesel p.u. in the 2003-2005 span. The prices there were many thousands lower than GM or Dodge of the same vintage. There seems to be a wide disparity between 4x2 and 4x4's in the asking price. A 4x2 is many thousands lower.
The price decline between a oil burner and a gasser seems to have two different trajectories. A gasser drops faster than a diesel. Even though I bought mine brand new, I still can't believe the crazed attitude of folks selling their seemingly 'solid gold' diesel pickups.
Which brings me to a querrie of my own: How many miles do you plan on driving said mystery truck? If it is a low number, I would advise looking at some large cube V8 engines and even a Ford or Dodge V10 gasser. Plenty of power if not mpg's. Some V10 jockeys have really learned how to drive these beasts to get the most out of them.
If you plan on driving A LOT of miles, like more than 25K per year, I would look for a 8 to 10 year old Diesel with everything you want already on it. Just as a yardstick, my neighbor has a 2001.5 CTD 2500/camper package/tow package with an original 378 thousand miles on the original engine. He bought it two years ago for $7000. It runs like a top and looks brand new.
As has been said, "case by case" and know what you are looking at. There are a few 'buys' to be had in any age or condition trucks out there. Your job is to find just one of them.
In looking on Craigslist I found a 2007 Ford V10 Crew Cab 4x4 long bed with 220K miles/10K on rebuilt engine and transmission: $9500. Here are a couple I found just now:
http://sfbay.craigslist.org/eby/cto/4292660528.html
http://sfbay.craigslist.org/eby/cto/4295547786.html
I have no connection with any of these.
happy hunting,
regards, as always, jefe
'01.5 Dodge 2500 4x4, CTD, Qcab, SB, NV5600, 241HD, 4.10's, Dana 70/TruTrac; Dana 80/ TruTrac, Spintec hub conversion, H.D. susp, 315/75R16's on 7.5" and 10" wide steel wheels, Vulcan big line, Warn M15K winch '98 Lance Lite 165s, 8' 6" X-cab, 200w Solar