Here is a data point for my local State University. I happen to work there, so I can verify that these numbers are pretty much correct. You can pay cheaper rent, but you'll pay back the difference in car mileage and/or roommate drama.
Tuition is (roughly) 40 percent of the cost. What really drives up the student debt is the cost of living. If we really wanted to do something about student loan debt, I think we'd do better to apply the same political pressure to the cost of living as we do to the rate of tuition.
Indiana University [1] Tuition: $10,388 Room and board: $9,794 Books and supplies: $1,230 Transportation: $1,030 Personal Expenses: $2,096
[1] http://admissions.indiana.edu/cost-financial-aid/tuition-fee...