You should soon get ahead of the repair curve on your new ride. I always budjet funds for these eventualities when I buy used. Part of the reason is that in many cases my standards are higher than thse of some of the folks that work on these cars.
I am a huge believer in PM. This means doing all the necessary things on a realistic schedule. If you do become a DIY'er make sure you always use new parts. A new part is always better than a used part regardless of the source.
Before you get to down on your situation ask yourself why there are so many folks involved in sourcing parts and repairing these vehicles. It's because they are worth fixing and maintaining! And like all of man's inventions, they need attention from time to time. Just as you do. I think I read somwhere recently that 81% of Mercedes cars built since 1973 are still on the road. Keep this in mind.
If I made a list of all the repairs my cars required over the years, I think the same items would keep showing up over and over again. The good news is that on a well maintained car almost everything that needs doing will be relatively routine.
It's also a good idea to establish an annual budjet for maintenance. For my cars it is about $800 per year for each car. Some years I spend more on one and less on the others. But it ends up being pretty close and there are really no suprises.
Good luck and keep your chin up.
1st In Class - Starfest Concours 2004
1st In Class - StarTrack Concours 2003
MBCA - Niagara Section