Dave, I just had the same conversation with my mom about taking out an huge loan so early on in life (I'm 21). I told her that I would rather take an extra 1 or 2 semesters off from school if it would mean that I would take out less money for training.
If I lived at home and trained, I would only need around a 10 thousand dollar loan to complete my training through my CFI. Working, the money saved from living at home, and cheap rates at my hometown flight school would allow me to accomplish this with minimal debt.
My instructor here at UND for the abbreviated PPL course, he is $92,000 in debt and by the time he is done paying it off, he will have paid around $150,000 or so, could be less, but his payments per month are $675. I would find it hard to pay off more than the $675/month on a CFI salary. So in the long run, he will have paid off a house. That is too much in my eyes.