State contributions to higher education (via taxes) have dropped dramatically in recent decades [1]. Ergo, tuition increases. (Universities drive up costs themselves, too, of course.)

Back in 1961, state tuition at UNC was less than $100 [2].

[1] http://www.amazon.com/Unmaking-Public-University-Forty-Year-... [2] http://www.quickanded.com/2012/04/virginia-foxx-paid-87-50-i...