Welcome to FT. You can't do it reliably, so I wouldn't attempt it. Based on what you've posted, it looks like you may be on a traditional legacy carrier. Have you looked at Airtran.com for ticket costs? You may find a less expensive ticket there between your departure city and ATL. There are other LCC's as well, depending on where you're coming from. And keep in mind, that sales do occur from time to time, if you don't want to pay the going rate.