International Flight?

I use yapta.com to track airline prices. You can do this before you buy tickets to help you know when is the right time to buy, and you can also do this AFTER you buy to let you know if the price comes down. I did this for a recent trip to Asia where my ticket price dropped a whopping $550 after I bought them. I had to pay a big change fee of $250 to United, but still, that saved me a lot of money.