As long as it has been serviced properly at the correct intervals and the price is good, -- go for it there are plenty of Mercedes around with 200 -- 300 thousand miles on the clock.
2017 Audi RS6 Avant Performance Edition. Range Rover Supercharged - Lovely!
More information about age etc would be helpful.
We've talked on this forum about 320CDI's with 500,000 & 610,000 miles on the clock. There are regular 400,000 milers and the engine is as tough as they come.
These cars need to run to be healthy.
THIS world record will give you a clue as to the quality of the engineering.
If you can find an expert (perhaps someone on this forum) to look at the car for you, then that is the way to go.
I saw an E class (210 series) for sale at a local dealer with over 550,000 miles on the clock. Original engine and the seats and interior were just so good it was almost beyond belief.
Another local guy who does business hires runs his S class diesels up to 300,000 before he sells them.
I agree with that; and it's true as with all cars. Volkswagen Polo engines are tested to the rev limiter for a week, and stripped-down showing little/no wear. City and real-world driving is far tougher on all components than cruising on the motorway all day long.
Remember the Nardo racetrack publicity stunt for the Cosworth 16v w201's? This sort of thing isn't new, but I thought MB stopped doing these kind of extreme tests. Do they change the oil in those 100,000 miles? It's still impressive, but it's not a feat of which an MB is uniquely capable.
I'd say 185k with service history to back it up is nothing to worry about. The one to look for is rust.