There are many reasons why schools have become more expensive over the years. The cost of health care, alone, is growing much faster than the rate of inflation.
But honestly, most universities went on a building spree over the last twenty years. Fancy dorms and labs and classrooms and athletic facilities really start to add up -- and grants rarely pay for them. As I said before, there are tons of inefficiencies in the university system. I just don't think they're in the classroom.
For a lot many schools, the donations and fund raising increases as they have a better athletic presence. In the long run, athletics doesn't really lose money for the school. Athletics at a lot many schools are self-sustaining.. especially after cutting off a few sports that were a moneysink. Big Time Athletics is Big Business these days with sponsorships, TV revenue, ticket sales, advertising and elicited donations.
Part of the reason they were much cheaper in the past is that government funding per student was higher in the past. When I went to college government funded around 2/3 the cost of my education. Tuition covered 1/3. This is no longer the case. There are other reasons for the increase cost in higher education but none of those reasons are faculty salaries.
Educational funding from the Govt to public schools has drastically decreased over the last decade causing schools to cancel classes and let go people. There's not much to do in terms of increasing revenue but to increase tuition, increase enrollment and such,.
Also, I imagine you didn't go to a state school.