I bought my first diesel in 2001.
For me the diesel cost ot admission wasn't too bad. I had a ton of points from the original GM card. The dealer could not believe how much he had to take off... The phone lines were burning up between the dealr and GM.... The rules had changed to a less generous plan, which I never took part in.
But that said, normally the only downside to diesel is the price of admission,,, after that staying in a diesel is easy. Yes the resale is there. And if I ever decide to go back to gas, I will do very well.