Pay your parents below market rent.

Seriously, once you leave you cannot go back. If you have a good relationship with your parents, stick around. I left home at 17 because I didn't have a good relationship with my father and never have had one. I'm sorry I don't. We're great phone buddies, tho.
It's a big step. Don't be too fast to "grow up." You have more time than you think. Best of all worlds is paying bills while you have the security of your folks.
CJ