The break point comes when you decide whether you like being passed or like doing the passing with your trailer hooked up.
In your case, given we are all intimately familiar with your situation, a diesel does not make financial sense for you.
You’re pulling (maybe? going to be?) a trailer that 1/2 ton trucks can handle so that, combined with the “cost” (which is decidedly more for those that pay retail for every service) makes a diesel less attractive for you IMO from a financial perspective.
Now if you want to own the roadwith your camper in tow, get a new diesel!
Still not certain why you’re after a truck that you admittedly can’t daily drive, when your goal was to have a daily driver AND camper puller.
Don’t let the rvnet ninnies scare you away from making the right overall decision for all your driving needs.
However, fuel being harder to find is NOT one of the reasons to not buy a diesel.....
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold