To some extent sponsorship
Tuition, car insurance, applications, standardized tests (okay I had to chip in $100 that I earned to last year's AP tests), club dues...
And this sponsorship does limit me to the cheapest of colleges that I can attend though, but otherwise, I enjoy lots of freedom to do my own work, extracurriculars, studying, and earn whatever passing grades that gets through.
And for the followup, I'm not leaving home for college, I may even stay home until I can afford a house down payment from a job. At least I don't have to worry about debt and I can do occasional visitations / sneak back on campus / attend youth groups where I keep intact with everyone I know.