I've got a PhD in math. I've been wondering this too. I remember that one of the institutions that accepted me, said, in the acceptance letter, that my offer

I've got a PhD in math. I've been wondering this too. I remember that one of the institutions that accepted me, said, in the acceptance letter, that my offer was worth something like $60k a year ($20k in actual stipend and $40k in tuition I wouldn't be paying). That was good for a laugh then, but it would have actual meaning now.