I had a 306 d-turbo. Engines on those will go well into the 200k’s. Had it for four years and barely cost anything but then I did a lot of bits to it myself. Good thing about these is they are very common at scrappies so you can pick up almost anything that needs replacing from there for cheap or alternatively from GSF / ECP.
I have a Cat D 206 at the moment and all that was wrong with it was a cracked rear bumper and a dented tailgate. It depends on what the issue was that made it a write off and how excessive it is. Over the winter is the best time to get Cat Ds as garages tend to bump up repair prices as they’re so busy.