I bought our 1990 190E 2.6 (M103) with 90,000 kilometers (55K-miles) on it. I sold it to my dad shortly thereafter, and he put most of the rest of the mileage on it.
I bought it back from Dad in August with 325,000 kilometers (200K-miles) on it. It's at 336,000 now.
The engine has not been open, not even any top end work. Did a timing chain for sleeping better only at 200K. Tranny seems pretty good too.
I figure we'll (my wife drives it) put about 30-40K klicks per year on it, and we'll drive it for another two years. (It's nice not having a car payment!)
When she has 425,000 (about 265K-miles) or so, I'll either sell it for very little or donate it. I bet it still runs good...
...this is one tough little car.
1998 C230 "Black Betty"