I'm not a DIY'er, but I do have a good shop to go to.

I'm willing to spend $800-1000 per year on repairs, but not more than that.

The main prob with my old 300E is the head gasket needs replaced (and a ty-rod end), but besides that it has a number of annoying things like badly bubbling window tint, radio antenna motor not working (so no music), heater fan not working (so I'm freezing half the year), scrape on one door panel, peeling clear coat. So it's not exactly fun to drive. But it's been pretty reliable. The blown head gasket was caused by a user error (me).