Are you going for a certification or an actual degree? Would you be taking classes through a reputable university that also has physical classrooms or a for profit university (I would advise against the latter).

Maybe a massive online course from an Ivy League/other well known college would be an option. There's courses in my field for only $600 that would involve a certification/possible degree credit if it were necessary for me.

Online courses are really a hit or miss on whether they're as educational as in person classes. Evaluation becomes an issue in classes that are completely online and don't even have you go to a physical place to take a test. If the class is just a means to learn information needed for an independent licensing or certification exam, then it won't matter how you learn the knowledge. I'm not sure what all is available in your field certification-wise or if you're seeking to get an associates or other degree.

Also, about the flexibility thing. Yes, they can be more flexible, but if you have tendencies to procrastinate, it's probably not for you. Online courses take a different sort of disciplined planning that physical classes do not.