Princeton has so much money that they could make it free for all undergrads and literally never run out of money.
> Financial aid covers the full cost of attendance -- including tuition, housing, food, books and personal expenses -- for most families with incomes up to $150,000 a year. Most undergraduate families with incomes up to $250,000 will pay no tuition.
https://www.princeton.edu/admission-aid/affordable-all
> Financial aid covers the full cost of attendance -- including tuition, housing, food, books and personal expenses -- for most families with incomes up to $150,000 a year. Most undergraduate families with incomes up to $250,000 will pay no tuition.
https://www.princeton.edu/admission-aid/affordable-all