MIT puts almost all of their course materials online and EdX offers Online courses from MITx, HarvardX, BerkeleyX, UTx and many other universities. Topics include biology, business, chemistry, computer science, economics, finance, electronics, engineering, food and nutrition, history, humanities, law, literature, math, medicine, music, philosophy, physics, science, statistics and more. At EdX you can even earn a certificate for passing some of the courses. Why have student loan debt if you can learn for free?
MIT Open Course Ware
http://ocw.mit.edu/courses/index.htm
EDX
https://www.edx.org/