I would never go out and borrow money ( even at 3-4%) to go invest it in the stock market. Even if you could refinance to a lower rate it makes more sense to me to pay off the debt. I had over $40,000 in student loan debt also when I finished school. It was such a freeing feeling to get that paid off. Nothing beats being debt free! My advice - write the check and don't look back. You'll be glad you did.