I think people seriously over-estimate how much marginal happiness (if any) that expensive graduate degree will bring. Many people seem to continue studying out of inertia and through encouragement of academics who have a vested interest in maintaining a large number of graduate students.

I'd suggest they take their undergraduate degree and go test the waters of where they think they want to work. Spend a couple of years in the field, even at a lower level, pay off a little of the debt they already have, and then if they like the field, and want to continue in it, they'll have a much clearer idea of the benefit/cost ratio of an advanced degree, and a better idea of which school and program will give them the best value. And if they decide the whole field is wrong for them, it's much easier to start afresh somewhere else. Undergraduate degrees are much more transferable from field-to-field than advanced degrees.