No one's ever said gas trucks have bad resale value, but gas truck owners like to make themselves feel better mentioning this nonsense X-hundred thousand miles needed for the diesel truck to pay for the upfront cost of a diesel engine, they never bring into discussion the resale value of a diesel engine.
I don't personally even think of the resale value of anything, I buy things based on what I need/want not slightly even considering what I get back when I sell it. I needed a 1 ton 4x4 truck, I wanted a diesel and a Limited trim. To me diesel is just an option just like a trim. Will I get back what I spent in extras on Limited vs going with a Tradesman or Bighorn? Probably not, don't care, just like I don't care about spending extra on a diesel engine which to be honest, I will never utilize to its full potential. Bought this truck to haul a slide in camper by the way, not towing anything super heavy.