The difference is between thinking about the now and the rest of your life. It's true that you'll probably draw a good salary from a front-end development job; you'll also keep up to date with technologies for quite some time. However, a degree, for better or for worse, is a gatekeeper for a great many things, which are very likely to be helpful later on.
If you're truly interested in these technologies, it's not like you'll lose your skills: you're very likely to keep working on front-end web development throughout your college career. But you'll also be earning a signal that you're a long-term thinker with a rounded education who can think strategically. $60-80k may seem like a great salary now, but eventually you'll be thinking about how to grow from that. Having a degree opens up many more positions to you, but also increases your surface area for new experiences, opportunities and ideas. In turn, that will open up your opportunities for freedom, self-determination, and simply making a larger impact in your field.
Hopefully, you can get scholarships to help with those college fees, but either way, because you can command a high salary as a developer, you'll be able to pay them off. They're worth it.
Gap years are good, though - I wish I'd taken one - and may help clarify your decision.
Finally, regarding those fees (and increasing your opportunity for new experiences), don't forget that you can go to college outside of the US.