For starters, there are two schools like that already: MIT and Caltech. I think most people rich enough to pull this can afford to buy their kids into Harvard/

For starters, there are two schools like that already: MIT and Caltech. I think most people rich enough to pull this can afford to buy their kids into Harvard/Stanford so it would take someone with a real principled interest in this approach. Starting a research university (which you need to attract top professors) from scratch seems really challenging though because you need to build up your grants and either poach existing professors or hire junior ones. You could start a teaching or liberal arts university but a lot of students who want to go on to PHDs or take advanced classes would skip based on that.