The real cost, as always, in getting a degree is the students time. Someone capable of getting a Masters degree, can, without too much effort, make $100K/year pretty quickly (If income is what they are interested in).
This is why education is normally inexpensive in other countries - students are having to forego all that income, so it's in the interest of the country, to encourage their populace to become educated - so they subsidize.
I think part of the reason why Education is so expensive in the United States, is they have a fairly regressive tax system, with poor social systems (in comparison to other first world countries). Health Care is expensive, Education is expensive. It's a very difficult country to be poor in.
I'd love it if the $6,600 Master Degree started a disruptive trend.