> And the purchasing power in America is about 3-4 times as high.

The median income in Barcelona ~34K EUR per year. The median income in New York City is ~42K USD per year.

    > If you're poor in America you just don't get to go to college.

What? Who told you that? This is untrue. There are lots of grants (free money) and loans available to low income students. Also, the university system in the US is much less rigid than Spain. In the US, many lower income people will first attend community college to get a two years associate's degree. Then, start a job, and attend night school at a university for another 3-4 years to get an undergraduate degree.