Education is not inherently expensive. The student loan mechanisms are what allowed the vast expansion of colleges as capital intensive enterprises. You can find a multitude of discussion about how cheap both public and private education was in, say, the 1960s. And that was with primarily state/institutional regulation. Which is to say the student loans were moral hazard crack to compared to state regulation.
For most subjects, one needs an informed teacher, a class room and some books. Somehow this costs vast sums now. Guess why?