I did not get a price range that the OP was working with. If mentioned elsewhere in the thread, I apologize.
He did say inexpensive, reliable, and easy to work on. I am surprised no one has mentioned a 90's Ford gasser. I also looked for a 7.3 Powerstroke for a long time, but they were all way overpriced, IMO.
I stumbled across this 94 F250 XLT 4x4 almost 5 years ago. It was in near perfect condition, original owner, 5 speed manual, 200k miles, and a new 460 just installed. Everything still works, power windows, mirrors, cold AC, etc. It's the tow rig for anytime the motorhome is not needed. I paid $4800 cash for it. No payments. Yep, gas mileage sucks, but it tows like a mofo. At less than half the cost of a Powerstroke in worse condition, I can buy a lot of gas with what I saved. In 5 years I've replaced a water pump, and a starter....although changing a WP on a 460 required a little work to remove all the stuff in front of it. Still pretty easy.
It also matched the color of my old boat of the same year too.
Just a suggestion if it is not going to be a daily driver.