I bought a 1999 F350 Powerstroke in 2001. King cab, 4wd, Lariat. Had 33k miles and I bought it for $29k. Best thing to happen to me as far as re-sale value was Ford discontinuing the 7.3 International motor in them. Nearly 500k miles pulling horses allover the US< and all I ever did was add a Bully Dog programmer, a front axle that broke on me in Florida with a load of horses on the trailer, and I had to replace the clutch one time at about 200k ,miles ( it was a 6 speed manual and manual locking hubs, my preference). Sold it this summer for what worked out to be about $30k. Guy gave me $16k and a 97 F-350 long bed, regular cab, 7.3 Powerstroke. 4wd with manual hubs, and automatic trans, manual door locks and roll=up windows and rubber mats. He had replaced the vinyl bench seat with cloth bucket seats and a console from another 1990's F250/350. If I could have ordered one in 1997, this is exactly how I would have equipped it. and it probably would have cost under $29k new. It had 58k miles on it! This will be the last truck I buy..it should last at least as long as I do .

Around here, if you can't find a good 7.3 motor in a junkyard for less than $10k.
I have been a loyal Ford man all of my life, but the tree worst mistakes they ever made was getting rid of the 7.3, the indestructible 300 in line six, and the Mercury Grand Marqui, I have a 2007 Grand Marqui I bought for $7k in 2017 with 23k miles on it. Those 4.6 v8s are pretty much bullit proof, too. 26 mpg and the trunk will hold as much as the newer little mini-van looking SUVs most manufacturers make now. And you can't beat the ride from that air-ride suspension. If you find a good one for sale now, they will be $15 to $20k. I bought my ole lady a 2018 Ford Escape last January, and I can't figure out how to get the lights on, the heat or air on, or the wipers without putting on reading glasses and squatting outside the door to try to figure it out. That Marqui will be the last car I ever buy, too.
In 1973 My granddaddy bought a 1966 Ford 3000 diesel for a few hundred dollars. We put a front end loader on it with a spear on it in 1974, When my grandma died in 2001 we sold it for $8500. No telling what it would cost now. and I bet it would be hard to find parts for one now.