As for the particular airport, i do not know which one is likely to be cheaper. You will most likely see Air-Tran come out with its rates for that period before SWA. Except for its higher priced business class, AT rates will generally be the same for all seats. With SWA, you have to play the game of checking its site constantly because it has several discount rates and to get the rock bottom rate, you often need to hit its site and reserve on the day it comes out with rates for that period, which will not likely be for a few months at least. Note that in other areas, we have found SWA's rock bottom rate to be lower than any AT offers.