I went to Boston University for my undergrad degree, one of the most expensive schools in the USA. Current tuition / room / board is $63k, and another $3k is estimated for expenses [1]. If you could lock in these rates, a 4-year degree would be $264k.
But that is assuming a lock-in. Costs increased 3.7% this year [2]. If there was a 3.7% increase every year during your 4 years, you would pay $279k for a 4 year degree. This is a $15k increase over 4 years.
What's even worse, because of the magic of compound interest, only 9 years after you graduate, yearly costs would be $102k per year.
I personally see this as insanity. It will have to self correct itself, because no one can afford those fees.
So how does BU get away with it now? Primarily through allowing any foreigner with the ability to pay in, regardless of their educational merits. BU has a massive amount of Asian, Indian, Eastern European, and Middle Eastern students who pay the full costs. Anecdotally, a man in my freshman dorm was the young scion of a wealthy family from Dubai, worth over $100 million.
US students rarely pay the full tuition, which is why the outrage isn't so large.
[1] http://www.bu.edu/admissions/admitted/tuition-and-fees/
[2] http://www.bu.edu/today/2015/bu-tuition-and-fees-to-increase...