Second, the price of the learning technology is dropping. Quizlet is an example. It is getting easier to actually learn the material and verify that learning has taken place.
What hasn't happened yet, but what seems to be the logical next step is cheaper or free credentialing: a trusted organization vouching for a person's mastery of a body of knowledge.
Kind of like a degree.
Now the costs of providing the education is going to zero. Instead of highly paid teachers lecturing tens of students at a time, Sal Khan is making video lessons that are viewed by tens of thousands. Instead of expensive textbooks, Wikipedia provides better information for free. Instead of recitation hours in a classroom, students are tutoring each other online or testing themselves with flashcards.
Traditional educational institutions are being left with a shrinking value proposition. They screen students (admission). They verify that students are doing the work and learning (testing). They graduate students (certifying). These functions are not what traditionally justified their high cost.
Of course becoming competent requires significant time and effort on the part of the student. But this doesn't mean that the means used by the student need be expensive. One can become very physically fit without joining an health club and hiring a personal trainer.
I'm not saying Quizlet does all the same things, but nothing about paying for extra education is what I would call niche.