I thought I'd chip in a few tidbits from my perspective as an ex-academic who's worked on a couple of different continents and seen the folks at various grades of institution.
1. The students and professors plateau in intelligence and ability at the level of decent state universities. University of Michigan and Ann Arbor, University of Illinois at Urbana-Champagne, University of Virginia, University of Arizona---their students and professors are every bit as smart as the ones at MIT or Harvard. They are less pretentious and less likely to be assholes, though.
2. No one should ever pay for a PhD in science or engineering in the USA. In any legitimate program, you are *paid* to take such a degree. Sometimes you are paid quite generously, as I was (about $55k/year plus subsidized housing, insurance, and lots of perks).
3. The instruction in basic subjects is on average better at a community college than a four year university. Obviously, this varies by school and subject, but you're better off taking those general requirements that would be several hundred person lecture classes at U of Wherever at your community college.
4. Look beyond the USA. The EPFL and ETHZ in Switzerland, which have the slightly more prestige than Caltech and MIT, charge CHF1200 per year in tuition for foreign students. You need to speak French or German, but you can pay for a lot of language lessons for that difference in price. Canadian schools aren't as cheap, but are certainly cheaper for an American than a US school.
5. Who said a bachelor's degree is four years? The fee that I'm seeing listed for an AP exam is $117. That's cheaper than any college credit from a traditional school that I know of. My school was encouraging me to graduate at the end of my third year. I had a friend who did it in two because she was financially strapped. That was a physics degree, mind you, one of the heaviest programs at the university, exceeded only by astrophysics and biochemistry.
On the other hand, the most valuable skill I have, what pays the bills and is very rapidly building my savings, is programming, which I have never taken a class in in my life. I learned it starting when I was 13 and had several years of professional experience before I got to college. Think about that. A bachelors in physics, another in math, a masters in biology (got thrown out of my PhD), and my high school hobby that has the highest market worth.