I think some parents also want to spend some of their money on a nice school with smart peers and lots of support and a great potential for personal growth and making connections rather than say a new Lexus. If this school is high status, and there is a perceived value, so much the better. Almost all the high status schools are very nice places to spend 4 years and get a good education.
Regardless of the nice new labs at the CC or honors dorms at flagship or the almost like a private LA school, these aren’t quite as nice.
Considering that the top schools actually do spend a lot more per student, there is a difference in value (unless they just are building water parks for every dorm, but I think that is another thread … and some kids might really, really enjoy that water park and daddy can spend).
If you can get 50% of people to fork over the full $70K and have a nice endowment, you can now open up FA to the rest of your applicant pool.