I think it depends on the Ivy in question(re your first point). On your second, absolutely agree. But again, say you want to do research work, or take a graduate course. In a "best in the world" environment, the average of your opportunity set there is going to be higher than a non-best-in-class environment.
You should also be careful about the top professors. The best professors are experts in their field, but you may be better off taking a class from someone who loves to teach, rather than someone who is an excellent scientist. Famous professors are much less valuable to an undergrad.