We pay for driver's ed and insurance. They know that any bad driving choices will result in the removal of their license. So far, six drivers and it's worked fine.
The reason I pay for it is because I shamelessly use them for errand runners. I figure if I want them to have the license for my benefit, I need to be willing to pay for it.
But that said, by about 15 or 16 they have automatically (without our direction) paid for their own toiletries, clothing, gifts, etc. They also pay for their own education after high school.