That's a question you have to answer for yourself. In general I would recommend buying something that you can easily write a check for (never, every borrow money for a depreciating asset). If I was talking to my kids, I would recommend something that costs no more than about 20% of their annual income (i.e., a $10k used car on a $50k income). I know that's a very conservative recommendation, but they can drive nicer cars when they can actually afford them. I don't know anyone who's accumulated wealth by buying toys they couldn't afford.

When I was younger and dumber I bought cars, bikes, vacations, toys, etc. that I couldn't really afford; it isn't worth the stress. Just my $0.02.