There are two countervailing effects going on: a drop in demand for college by states, and an increase in demand due to more college-age people. If the latter effect is the important one, then Hristov's original point (regarding reduced state subsidies for college) is irrelevant. If the former effect is the important one, then spending should have gone down.
And if Hristov believes the decrease in demand due to reduced state spending caused prices to go up, he should explain why he believes college behaves so strangely relative to other goods and services.
And if Hristov believes the decrease in demand due to reduced state spending caused prices to go up, he should explain why he believes college behaves so strangely relative to other goods and services.