200 large ain't a lot today. But where I'm at in life right now (mid-40's, married, no kids, healthy balances in retirement funds), it would pay-down about 2/3 of my mortgage, and we would probably use cash to pay-down the remainder. And thus, free of our only debt, we would certainly be able to enjoy life a lot more, perhaps allowing one of us to semi-retire at 50 or so.
If went back to age 13, I would certainly have had a lot more fun in my H.S. & college years, and would certainly be more prosperous now.
But I'm happy where I'm at now, so that little boost would go a long way towards making my remaining time even more enjoyable.
I'll take the $200K.