After one of Mark Edmundson's op ed pleas for students and parents to consider college as non-vocational, I had a look at the University of Virginia's tuition and fees from the late 1970s to recently. Comparing this against the minimum wage, I found that a student could have earned the 1978-1979 tuition and fees working a bit over eight weeks at the minimum wage. For the 2011-2012 school year, it was more than 38 weeks.
Well, 38 weeks * 40 hours * 7.25 per hour = $11,020. Your total tax bill at a yearly income of $11,020 is very close to $0 (and with educational credits I suspect you would get back slightly more than you pay).