Vehicles in general are a black hole but wondering where that balance point is at. I went through this years ago.
In 2012, bought a '04 Ram 2500 with the 5.9 that had 100k. Bought it to pull my toy hauler. I bought it for 18k...crazy to think of that price today. But it was also expensive for me at the time as an active duty E-5. I sold it in 2020 with 199k on it and I had to put some love into it - typical Dodge ball joints, brakes, etc, but nothing crazy.
Towards 2018/19/2020, it was starting to get long in the tooth. Adjusted the bands in the 48RE but the signs of needing a rebuild were in the future. A/C didn't work at low speeds (needed charged, had a leak). Hated, hated that transmission for towing. 4 speeds was not enough. Was going to need a paint job. Do I put 10k (paint/transmission/AC) into a paid for truck or go full retard and buy a new-to-me truck? Obviously 10k was too much to spend, so instead I spent $44k on a 2016 with the 6.7 that had 9k miles on it
On the plus side, I literally sold my old truck for what I paid for it. So my out of pocket costs was the interest paid on that loan plus maintenance items during ownership.
I'm just under a year out from having THAT one paid for, but it's been on strict towing only duty and garage kept, so it's at 45k on the odometer and kept clean and literally only sees the sun on the weekends I pull the trailer.
I suppose eventually my 2016 will have the same fate as my 2004, so I reckon the best I can do is prolong that time as long as possible? At only putting 6-8k miles on it a year, maybe by the time I need to buy another truck, they'll be $250,000