Show me another twenty year old car, except the VW beedle, that is as easy to maintain and as reliable as our old smudgpot diesels. The parts are cheap and easy to find. Problems are fairly easy to diagnose and fix by a competent DIY.
My 84 300D was a gift from a long time friend and I've put about $4,000 in parts into it. Everything works just like it did when it was new and at that time it cost someone around $50k for it.
I've had older and later MBs and none compare to the reliability of these early turbo diesels.