>At the same time many more students are going to college than they used to.

In terms of cost this statement doesn't make sense to me. There are plenty of economies of scale in education. One professor can educate an undergrad class of 100 people for barely more than what it costs to educate 10 people. While the effort for checking exams multiplies directly with the number of people, many of the costs are lowered the more students you have.

The marginal costs per student almost go to zero if you have enough students.