my experience is a bit different because my labor cost is free of charge and I enjoy working on them because they are such fascinating pieces of machinery. e.g. take apart the 5 spd NAG1 gearbox and how it operates to get 5 forward gears and 2 reverse gears from 2 planetary sets - I really want to meet the guy who initially thought it up - but then I also am currently trying to wrap my head around the new zf 9 speed automatic transmission - its "confusing" to make it easy for you.
now back to MB.
people think that MB are cars that will work for decades without maintenance at all, this is not the case, it does require maintenance but at different intervals. Its parts are a bit more expensive because they are made to a higher level of quality and workmanship. Thats why it drives so different than any japanese or american car.
The other problem is that some repair shops amp up their charges as soon as they see MB roll in. when I was in Karachi I met a guy who paid about Rs 10,000/- for front wheel bearing service on his W210 - I was shocked to hear that, it uses regular wheel bearings that are also fit in a lot of other cars and are packed by hand - I could not understand how it ended up like that. The poor owner was given the reference that civic wheel bearings are Rs 5000/- so naturally expect 10,000 for MB ones. .... SHOCKING.
99% of MB in Pakistan are owned by "bhai alhamdulIllah sirf aail badli karata hoon" baaqi sb jenyan hai - set gaari hai" - the car is usually beat to death and is requiring all sorts of maintenance. The ride quality and performance of any worn out MB is still better than most cheap econoboxes hence people think that as long as its moving its "AASUM" - never buy such a car at asking price. It requires a big purse of money to repair.
then come the driver hazraat who screw it up further and the low percentage of "rim shim deck sheck" guys who pay no attention to the effects of their "awesome street cred mods"
Best buy a car in reasonable amount and bring it to control specification - then proceed to run it like it should. It will work for an insanely long time - remember that these are favorite for taxi purpose - taxi operators are the cheapest bunch in the world.