Not the interest of the student loan, the 'interest' of the opportunity cost of paying $4000-$6000 year instead of some other use (eg personal or retirement sav

Not the interest of the student loan, the 'interest' of the opportunity cost of paying $4000-$6000 year instead of some other use (eg personal or retirement savings, or saving for a house). There is a huge forward cost in their financial quality of life because of these early debt payments.