I don't know if any of the Ivy leagues are worth the money. Not that they are not very good institutes, just not worth the money they take you for.
Kind of like a Lamborghini, a really cool car, and if you can afford it, hey it's your money, but do you really need to pay that much to get from point A to point B? Kinda overkill. Just never considered overkill a great investment. On the other hand I was neither wealthy enough or smart enough to get into one anyway....so my opinion really doesn't matter too much.
Part of what you get out of an Ivy league school is the connections you make with fellow students, the faculty, and beyond the immediate campus. I actually started at an Ivy and finished at another private school in the middle ranks.
One of the most shocking experiences at that other school was walking out of an interesting class discussion with a friend and continuing the discussion at which point he turned and said, yeah, whatever, I'm not that interested. We were both in the same major, for which this course was a part of the requirement, and there was this lack of curiosity. The better school you go to, the more likely it is that you are going to be surrounded by more motivated, more curious peers, and the more peer pressure there will be to be equally motivated and curious. Some people are very self motivated, most respond to their surroundings to some degree. It is true in sports and it is true in academics.
Because of my time at an Ivy, ten years later I went into business with one of my friends from there and we did well enough to allow me to retire a few years early. The chance of you peers going on to be successful/influential as professionals goes up, the better the school you attend. Doesn't mean that you and your friends will not be just as successful or more so at State U, or anywhere else, but the odds just get longer. In my case, I got a very good return on my (my parents) investment in an Ivy.
And I actually grew up in Storrs so went to EO Smith the local HS, and part of what made the Ivy possible for me was that about 2/3 of that student body was Uconn connected and the peer pressure I experienced was to succeed academically - I didn't want to be the screw-up amongst my friends which was more motivating for me, than anything I personally brought to the table.
I think if all you are looking at is the academic course work and the faculty, with a completely self motivated kid, you are right - an Ivy is probably not worth it. But like the chances of success for the 'average kid' growing up in a college town vs. an inner city are very different, so too are the chances for success for a college kid based on the surroundings.