It's a private univ but the research funding is through NIH/NSF grants. I can pay for myself by TA-ing but the univ has a cap on the number of people in 1 lab that are TAs. And the lab also needs money for equipment, sequencing, etc. The univ only pays the professors' salary (and mine if I TA)
The reason I chose US over Europe was because my funding was guaranteed for 2 years here while I would need a scholarship for Europe. UK was the worst - expensive, no real funding options from the university, and some places charge tuition during a PhD!!! Some of the Scandinavian univs did have stipends, as did the Max Plancks but by the time I found out I had made huge lists (30 univs, ~200 profs) for the US and didn't have the energy to re-do it for Europe.
My friend in ETH told me their stipends go from 50-70k francs/year.
@Grinner
I'm a PhD student; those extortionate fees will one day pay my stipend
But yes, my classmates who are from the US have student debt and the amounts are insane. It's not a surprise that someone promising free tuition in public univs got support from college kids.