For the 2004/2005 academic year, the average annual cost of a four-year public college is $14,640 and the average annual cost of a four-year private college is $30,295. (Source: The College Board's Trends in College Pricing Report 2004.) The total figures include five expense items: tuition and fees, room and board, books and supplies, transportation, and personal expenses
Well, using those numbers as an average, not counting for inflation...

Public College: $234,320
Private College: $484,720

Thats quite a bit of money!