I'm defining "afford to go to college" as "have enough money to actually attend if they choose to". The number of people who actually attend is a lower bound on

I'm defining "afford to go to college" as "have enough money to actually attend if they choose to". The number of people who actually attend is a lower bound on this number. A quick google search yields an average cost of $9k for a state school, $22k for out of state, and $31k for private. Maybe the expensive side of college is "mortgage-sized" debt, provided you are comparing to the cheapest mortgages.