Depends on what you define as “worth the money”. If it means securing the highest paying jobs, than often no. If it means becoming an expert in a certain academic field, than often yes, its worth it. If you want to study under great academics and do research for famous scientists, Ivy League may be a good idea. If you want to start a business, a good internship might be a better use of your money.
That's why I made a distinction between hard sciences and humanities.
The vast majority of Ivy faculty on the humanities is commie. There is no way of putting it mildly. You can't study under great academics in these areas, unless you become yourself a flaming liberal.
How much do undergrads see of these great academics? For getting your PhD, yes. Particularly since if an employer sees an MIT PhD, he won't even ask where you got your BS.