> you can get a masters in public health at a school that doesn't cost 80k a year in one of the most expensive cities in the world

While I agree, there is a clear benefit to the student, and to society (through the student's productivity), in learning from the best teachers with better resources, and in a community of the most brilliant people (which tend to become very expensive). I want public health professionals that come up with brilliant solutions to our problems. Anyone in any profession I think would choose that avenue of skill acquisition over the discount option. People in finance go to NY, people in IT go to SV, etc., for good reasons.

That said, it is a matter of degree. NYU seems to be near one pole of extra cost. If you are in California, for example, there are at least two public universities that are considered better than NYU.