Last Feb.(2019) I bought my 06 3500 SLT Lonestar dually 199000K miles for $17,500 credit union was willing to loan $23,500 for it, I loaned the money to myself out of my 401K loan feature 4.3% coming back to me, vs. 6.9% which was best the credit union would do on a 13 y/o used vehicle.
That was from an independent dealer vs Dodge dealership which would probably be asking closer to a KBB-NADA etc. valuation price, it might be more effective to see what insurance value would be if totaled in a wreck, that at the end of the day is the "real value" separating the emotional attachment from what one thinks a vehicle is worth.
If you can document any upgrades, repair history, or recent repairs that can be used as justification even with insure-ability estimations for a better justification of asking price for the vehicle, the Cummins engine brand is a plus, but at end of day it is installed in a older vehicle not so much, and here is why.
From my own experience and I probably should have negotiated my price down some knowing what I now know learning the hard way.
It needed a paint job refresh no corrosion a lot of chips and bed paint down to bare metal in a few places, pass side fender wheel tub cracked, decent vehicle suiting my needs....but rest of the story, those things you don't notice until the ink dries on the final bill of sale and drive it a little,
Needed to defrost windshield now that it is cooler morning blend door won't shift to defrost still living with that don't feel like ripping into dash but no way otherwise to repair it apparently,
6 way power seat is about 3 way now living with that for now didn't find that until 1st road trip and trying to make seat "comfy on long trip" cushions in Dodge suk compared to my GMs.
Pass side mirror didn't pan/tilt new convenience switch and fix bent pin in mirror harness at mirror,
12V convenience plugs don't work wire burned and undersized to begin with from factory,
Odd vibration at sustained highway speeds just 5k after buying, only to find out why with awful grinding noise that the front bearings are shot.
Back seat once folded up for storage vs. people, difficult to fold back down
Now this past weekend I got my "education" in crappy design of cross over cable between the 2 batts can over charge 1 battery and undercharge the other because no voltage regulator in the alternator, PCM controls that and if it sees under volt on 1 batt. PCM says charge baby charge never mid you are zapping the opposite battery not needing the charge with 17V and boiling it over.
All that said I do have a stout engine, wimpy trans but I knew that much about the Ram platform the other stuff sort of threw me for a surprise, not dealing with DEF and later "tree hugger stuff" is a plus.
I realize I bought a used vehicle it is what it is, I'm mostly satisfied with the buy I'm just a little missive with the "ancillary" issues with the truck so soon after purchasing it just 7K on it since buying , I almost afraid to ask what next, & my apology for digressing; just after truck letting me down more than I thought possible so soon after buying it I needed to vent a little.
Attention: TDR Forum Junkies 
