I’ll put it another way. If your kid is driven, he/she can figure out life at a state school fairly well.
I’ve seen kids at private high schools here in the Bay Area whose parents have to ride them to do their homework. They may get good grades now but I wonder if they would adapt well to the “take no prisoners” aspect of a large state school. Those are the people that go to a Boston University, Grinnell, Swarthmore (if they can’t get into an Ivy). Because if you think an Ivy isn’t worth the money then what the heck do you do with the second tier privates??