This is bad. You've been paying for five years, and you own NONE of your house; you might just as well have been renting. This loan was not in your best interest.
Since you now have $800 that you're not used to having, you should plan well and use it well. I'd suggest splitting it three ways: One portion towards house principle, one portion towards retirement savings, one portion towards short-term/emergency savings. These are ALL essential for financial stablity, and you shouldn't sacrafice any of them for the others.
Also, it'd be smart to see where you can tighten your belt, spend less in whatever area it's possible, and see if you can't put MORE than that $800 towards these three essentials.
Lots of assumptions here. We don't know what the original downpayment on their house was. Maybe they put down 50% of the purchase price and did the rest on an interest only loan.
There are times for interest only loans -- We chose interest only because with only one income, it reduced our monthly liability in the chance that the one income went away for a while. However, we do make principal payments on top of the interest only to build more equity in our house (and we put down a significant portion of the purchase price).
I agree that you need to split three ways ... in a few months. First, you need to build a better emergency fund. I would stick with the 6 months of living expenses above that are quoted. Once you've funded that, then I would look at buying down mortgage, and funding IRA.
However, there are many variables here:
1) is the income in an at-risk industry or seasonal profession or commission based ? If so, you may want MORE emergency fund.
2) do you have any equity in your house ? When you bought it, did you put anything towards the purchase price or are you 100% mortgaged ? Also, what was the timing... ie. how much has your value gone down ? Are you paying PMI ? If so, try and get rid of the PMI - it only protects the mortgage company, not you.
3) I don't remember, my brain is tired.
good luck.
oh yeah, to the person above who said that no one is refinancing ? We are doing exactly that. We are lucky to have good credit and we had a nice bonus check from work, so we are putting more equity into our house, refinancing the rest, and dropping our interest rate to 3.75%. We are saving a ton each month (although some of that 'savings' is false since it is our equity reducing the payment required). We plan to keep paying at the old monthly rate, thereby increasing the principal payments we were making.