I have been able to take advantage of lower fares during a sale by using the Travel Center screen and changing to the lower fare....however, in order to do this, the lower fare must be showing as "available" on the booking screen.If it's not all of the seats at the lower sale fare have been sold out. You can take the chance of cancelling your original ressie and "hope" that this opens up more seats at the lower fare, but, it is risky to do this. However, I've had very good luck just checking on a daily basis. It seems as the travel dates get closer and seats aren't filling SW opens up more seats at a lower price.I've managed to get our fare down to $116.90 each total rd trip from PHL to MCO 12/10 thru 12/17 since the original booking date in July. They started at$176.90 total rd trip. So, I've now got a $240.00 credit for our next trip.....
Initially the return portion of trip was not available at the lower sale price, however, I checked daily (sometimes twice a day) and sure enough, they opened up more seats at the sale price and I jumped on them. I've been lax in checking the past week or so, though, because I really don't think they'll come down any lower at this point. Of course this only works if you're traveling during slower times. I really don't think it would happen over Thanksgiving, Christimas, or Easter or even any of the three day weekend holidays. It works for us because we tend to travel at off times.
I can't figure out any other way to do this with DING fares. I am also trying hard to keep track of my credits.
