I own a 1997 S320 and i've had it for a year/40 thousand miles (115k-155k)

I've replaced the evaporator core, which was $2400 in the shop or $500 and a month DIY.
The sway bar bushings and links which were $40 for links and $15 for bushings DIY. Dealer quoted couple hundred.
2 Headlight lenses were cracked, dealer quoted ~800. DIY for $80
I replaced the stock radio/tape with in dash CD for $300 from perfectmarket audio.
My window switches broke and i replaced them, didn't even bother getting quote from dealer just DIY.
I've have tire wear problems, and the recommended michelens wear out too fast for me.

Basically i'd say if you're a mechanic this car is a fine one to own. But if you're going to take it to the dealer to get it fixed it'll be pretty brutal. I enjoy it though. Vacation drives aren't completely DREADED anymore. We put 2 adults and 3 teenage kids in it and drove ~600 miles and no one was in too much pain.