I own a 2010 S212 RWD E350 M272 non Cdi wagon with 55,000 miles.
Car is now 14 years old so plastic and rubber parts are starting to go hard.
Wagons - at least AFAIK those out of Germany nearly all have rear airbags.
My car was under a 10 year factory extended warranty and the airbags were replaced at the 10 year mark (FOC) It's an age issue rather than a mileage one.

A problem with a transmission control module required a multit thousand dollar replacement but now these modules can be repaired by after market technicians.

Other than that car has been fault free. Change the oil every 5000 Miles - not as the factory recommended. Service annually at dealership - minimal costs.

Huge load area in the rear with the back seats down - more usable area than most average SUV's.

The technology is primitive compared to my W213. I wouldn't be overly worried about it on a 212. Lots of aftermarket fixes.

Tyre wear is a bit concerning - wearing out on the inside of all 4 wheels.