Looking at the numbers a different way...

You're considering a $20K/year drop in income that has two benefits: (a) a lowering of your loan payment by $200/month for the next 10 years, and (b) loan forgiveness of the balance at the end of that time.

(a) works out to $2400 per year, so subtracting that from the $20K/year drop leaves $17.6K per year.

Taking your first paragraph at face value and worst case, you have $18K at 8.5% and $87K at 6.8%. This means you're paying interest at a blended (weighted average) weight of just under 7.1%.

(I'm ignoring the tax deductibility of the interest, but I don't think it will affect the outcome much.)

Assuming your payment is fixed at $300 per month and the remaining interest capitalizes and further accrues interest at the blended rate of 7.1%, over 10 years your remaining balance would grow to $160,107.50.

So what is the rate of return on investing $17.6K per year for 10 years and ending up with a payoff of $160,107.50 at the end of 10 years? Well, that means you're turning $176K of lost income into ~$160K of loan forgiveness in 10 years, which is the same as taking that amount of money and putting it into a savings account in which **you would be paying the bank 0.1458% interest!** That really doesn't make financial sense when you have the alternative option of taking that income and investing it in loan paydown at a rate of **7.1%**.

I agree with the other posters, if you want to work for a non-profit, then go ahead, but from a purely financial point of view it doesn't make really any sense with the numbers you gave.

Oh, one other comment. It sounds to me a little like you think the grass is greener with non-profits vs. other companies. It sounds to me like you're in your first job out of college and are assuming that non-profit means that there are not office politics or people who are difficult to get along with, or other similar thoughts. I sincerely doubt that this is true and strongly suggest you do your due diligence to confirm your assumptions before making a move. Perhaps talk over lunch with someone you know who works for a non-profit and ask for the straight scoop. I haven't worked for a non-profit (unless you count the start-up I worked for :-) ), but I have worked for a number of different companies over the years - some are somewhat better than others, but they all have warts of various kinds.

Good luck.