Originally Posted by Goat Rodeo
1) Have you own place and are financially independent
2) Can comfortably save/invest at least 1/2 your after-tax income
3) Can live a comfortable lifestyle including good food, drinks, and company
4) Travel frequently and learn new things, enjoy freedom
5) Pay off all your credit card balances monthly or use 0% APR cards wisely (E.g. never pay a finance charge, ever)
and still have the cash leftover for a M3, tires, maintenance, and gas
You're fine. I would say that requires min. 200K/yr in the USA for a single person.
As a single guy in my late twenties: when do you ever "have no responsibilities except enjoying life?" Unless you are completely bankrolled by someone else whatever income you have has to go to rent, tuition, food, dating, investing, traveling, insurance, clothes, etc. all of which add up to far more than a fancy car payment. A M3 is a suitable purchase for someone who makes 200K before tax and still has responsibilities, even if single.
As a fellow late-twentier, I would strongly echo the above. Save at least a year of salary, then, if all of the above conditions are met, knock yourself out.
Depending on where/how you live, that's $200-$400k a year.