take look the number first

https://admission.princeton.edu/cost-aid/financial-aid-numbers

For example, P, may be the most generous school,

Financial Aid by the Numbers

Students admitted to the Class of 2022 who applied for aid with family incomes up to $160,000 typically pay no tuition.

Do you believe their family incomes (a FACULTY and an IT staff) and assets (additional house, may be 529 plan,...) below the number? 

They may have to pay a part of tuition...