2 How rational of an estimator do you feel this to be?

As a yet-to-graduate student, it is difficult to think about the burden of starting to pay back the student loans and the weight of all that debt. Perhaps we need to think about student loan debt in a new way. We will take on debt of $20,000 to $40,000 or more for a new car and not think twice.
But we start to panic when graduating with $20,000 to $40,000 in student loan debt.
The car will last 6–10 years, but your education is an investment for a lifetime.
In Chris Farrell’s article “College Degree Still Worth the Cost Despite the Risk,” he quotes a study at the Brookings Institution that shows the return on investment for a college degree has been about 15% a year for the past 60 years. Not a bad return, given that the stock market has only shown a 6.8% return on investment over the same time period.
However, with college, like any investment, there is risk involved. If you are looking at college as just a way to get a higher paycheck, there is a risk that a job may not be waiting for you when you graduate. In fact, your financial return may differ based on your major.