If you don't need to tow24/7.. not worth the money.. If a Diesel breaks.. and you get out of the shop for under a grand you're doing really good, Hell 1 injector alone is 350$ just for the part, it's all personal prefrence, some people just have to have a diesel, i personally love my 6.4 2500,if it is modded you need to make sure they are good mods and supporting mods were done, " if it has a tunner, did they upgrade the tranny to take the tq/hp?" or are you factoring in a tranny upgrade for 4k in the near future? Unless you know the owner personally, id be cautious. And mind you. the hemi will get better mpg, parts are cheaper, and a few grand and it can be outfitted to tow a lot. my 2 cents