But its nuts now. People rack up 15k/year when tuition is 4k and books are 700.
That doesn't seem nuts to me. Tuition and books are about $5,000 by your estimate. Living expenses account for the other $10,000 a year in loans, right? Lets say you are a college student who works 20 hours a week 9 months a year and 40 hours a week 2 months a year. The other month you are not working either because of Christmas, moving in/out, finals, etc.
Your income from that job is the minimum wage of $7.25 an hour. Your annual, pre-tax income is $7,540. You are probably going to pay at least some tax on that income, so you take home $6,500 a year. Plus the $10,000 above. So that student is living on $16,500 a year. That seems pretty mustachian to me. If your rent is $400 a month, and your food bill is $200 a month, and your transportation costs are $100 a month (bus fare, no car), you are spending $8,400 of that money on reasonably priced necessitites. Clothes, health care expenses (contacts, glasses, prescriptions, advil, condoms), activities, dining out, alcohol, any car expenses, travel to and from home for Christmas, supplies for any class, etc. are all about $10,000 a year. I don't think that is incredibly excessive. Sure, it isn't mustachian, but it isn't exactly buying NFL tickets and eating at 5 star restaurants either.