As with most cars, it's not how much it cost to maintain a Merc but more so with how much you pay somebody else to maintain your Merc.
Some people go broke trying to pay for a new one while others go broke trying to keep an old one running, lol.
Truth!
For instance, on the Silverado we just bought, the parking/turn signal/DRL light housing on each side are cloudy and no amount of cleaning the outside of the lens does anything---the cloudiness is inside.
Bought a pair for $12/ea. Hate to think how much something similar would cost for a Mercedes, BMW, Lexus, et al. Hell, I even bought a pair of replacement headlamp housings for it because they were so inexpensive...the pair was under $90.
Of course, with GM selling like a half million examples every year of that truck sure makes replacement parts cheaper, unlike a car that sells maybe 20K or so each year. That and the parts aren't all imported from Europe.
And as an odd aside, I read a few days ago that VW has managed to sell only around 300K vehicles so far this year in the U.S., which really pales in comparison to the again half million or so pickups Ford and GM each will sell this year. One vehicle from GM and Ford outselling the entire VW lineup of vehicles...mind boggling. The article was written about will VW actually remain in the U.S. market, given its falling sales.