My HG DD21, who sounds a lot like your son in some ways, decided to take a couple of years off from formal schooling after high school to work while simultaneously attempting to start her own business. The bloom is off that rose now - she has discovered that there are still some things about art and about business that she doesn't know, and she probably needs to learn them in a more formal setting - so she is going to be enrolling in college this January working toward her BFA in photography with a minor in business.
In retrospect, taking a few "gap years" was probably the best track she could have taken, because her task commitment when she doesn't see the point of something is atrocious. Now that she sees the need, I think her chances of following through and completing her degree successfully are a lot higher than they would have been if she had continued college straight out of high school.