In the 20-30 age range, own a <10 year old BMW 3 series. Currently as a university student, I do mostly odd jobs and a little buying/selling on the side, and that's enough to cover maintenance.

They're not as expensive to maintain as you think, and even downright cheap if you do any maintenance yourself. The key is preventative maintenance, don't wait for something to break, don't wait for the car to tell you it needs an oil change, do it before it's needed. I've owned it for over 3 years and close to 100k miles, and it's only broken down twice, and only had to be towed to the dealer once in that time.

Once I graduate from my masters program, I plan to get a 2006 Maserati Coupe GT 6 speed manual (actually rather rare), and even that is somewhat cheap to own compared to some cars. I expect around $2-5k a year to drive 8-10k per year. Obviously there are some things that are extremely expensive like clutch replacement and such, but those are not a common occurrence. Overall, luxury and exotic cars are actually rather cheap to own compared to what most people think.