new 6.0 isnt bad, all diesels are going to fetch a premium. nature of the beast.

stay far far away from dodge. go through suspension and chassis components like crazy as well as wheel bearings and none are cheap. stay away from the V6 that ford used in the early 00's, actually stay away from V6's period no matter which truck you get. GM the 5.3 is about the most solid motor they have right now. And for what you sound like you will be doing stay away from 3/4 ton and up. parts start getting crazy expensive.