Here in New England, when you are left with a pile of rust after about 10 years, neither gas nor diesel is worth much. I would give the diesel a nod of course, but I can tell you trade in on my truck this past week at the dealer was < $20k.
Then again, I don't buy a vehicle because it might have good resale. I buy it for the job it needs to do. It's a tool, not an investment.
The truck has been well maintained, this is not from abuse, it's just a fact of life up here if you drive in the winter.
For those of you that mentioned injectors, etc. I would agree the recurring maintenance on the LBZ really has not been much more than a gas truck. Oil (full syn) is changed via DIC at ~ 10k miles, fuel filter very 20k miles. I have never had ANY engine problems. Ever. No injectors, water pumps, nothing. This is why it is a shame to have the chassis rot out from under me. Love the powertrain, but the chassis is giving up on me.
I don't expect a gas truck to last any longer in New England, that's kind of the point, after 10 years in the salt you need to replace a vehicle. The cost of ownership of gas will be less and the truck will haul what I need it to.
If I lived where a vehicle may last 20 + years, or I was driving 50k + miles/year (I don't) then I would not hesitate to get another diesel. I have nothing against diesel, I like it! Just doesn't make $ sense in my case.