There's no getting around the fact that high-end cars are expensive to keep up but they can be very rewarding to own and drive and the good ones are built to last if kept up properly. Do your homework and read extensively on these forums, and check with experienced techs before you buy, they'll know what to look for..
IMO it's best to stay away from the top-of the line models as they have the most bells and whistles. I've had good luck with Three and Five Series BMWs and Audi A4s from the late 90s-early 00s.
Infinitis and Lexi will tolerate lack of maintainence or abuse better than the Euro makes, at least that's the consensus.