Your sweeping generalization is off-kilter and disproved, Terry.
Ha ha, if you said it Cal, I MUST be disproved, yeah? Only problem with that is you're talking about your experience with ONE Mercedes, while I'm talking about my experience with MANY. Yeah mate, when I was a soldier I worked a second job to support my family working at a full service garage, and I saw MANY Mercedes' that had failed prematurely.
Usually it was electrical issues that warranted enormously expensive replacement parts, (ignition/fuel injection parts were horribly expensive and nearly impossible to obtain from the Australian distributors, before the internet fixed most of those issues) but just as regularly, mechanical failure was a huge issue too.
The guy who started re-inking computer cartridges in Melbourne made a fortune. Before he made a lot of money though, he bought a new 1980's Mercedes 230E. By the early 1990's, it was blowing a cloud of smoke everywhere it went, so he brought it in and asked my boss to do a full rebuild. Back then a replacement reconditioned engine for an Australian built car was around the $2K mark, but due to the ridiculous cost of Mercedes parts, the quote for a full reco was $8K!
My boss was sure that the owner would tell us to forget it, but no, he's made a fortune re-inking cartridges, and he happily paid the $8K. Sadly a few months later it had some sort of electrical fire after he washed it with a high pressure hose, and burned to the ground in the owners driveway. Oh well........
But the thing that reminded me of this story was your claim that somehow the savings that you've made by driving your 16 year old Merc has put your son thru college. You see, my boss was one of the few mechanics in the area who would touch crappy European cars like Mercs, BMW's, Volvo's, Saab's, Audi's etc, and he told me that the reason that he'd decided to become the patron saint of Euro trash cars, was because they'd put both of his kids through private school, and paid for another house when his wife divorced him.
Oh, and your economy figures are a little "Light on" mate, you might have forgotten to add the 50,000-odd gallons of gas you've put through it, not to mention all of the other items that are a true reflection of actual running costs. In reality, the $80 that someone forked out for that thing when it was new was only a deposit.............