In my book I discuss the role of debt in paying for college in some depth, including talking about what it would take to pay back $20,000 in student loans.  Here is another way to think about the question based on recent data.  The table below shows average earnings of 25-34 year old worker by level of education.  If you were completely average, how much debt could you pay back over ten years at 8% and still have the same remaining income as you would have had if you had stopped with just a high school diploma?

It turns out that if you earned your four-year college degree and were average, you could be making payments on a $100,000 loan and still have as much (or maybe it is more accurate to say as little) to  spend as if you were an average worker with only a high school diploma. By the way, there are many reasons to challenge this analysis, including the fact that there are many other differences between these two populations than just the degree earned.  So don't go out and borrow $100,000 because I said it way okay.  In fact, I encourage you to only borrow what you need in order to successfully get through college, and if you select your college with net cost in mind that shouldn't require this level of debt.  But keep this chart in mind when you are talking to someone who thinks you should avoid borrowing even $5,000 per year to get through college.  The odds are that will be a smart investment.