I agree and should have been much less implicit in my argument. Perhaps state universities once (< 80's) charged very little because they (1) got lots of money from the government with the mandate of providing affordable education and (2) students didn't have access to grants/loans to pay more anyway.

Now, the "price" is higher (which is used to create the graphs in the linked article), but the effective cost for the student hasn't increased quite as proportionally because he has a government voucher to use.

Greatly oversimplified, I know. We understand what someone means when he talks about the average price of a gallon of gas at a gas station, but we don't have a common definition for the "price" of education. Out of pocket not counting grants/scholarships? Do we discount the cost if the loans are at a below-market rate because of government guarantees?

Heck, even the gallon of gas "price" is hard to define. Marathon gives me back 5% on gas purchased with my Marathon card. What's my average price per gallon?