the ticket purchase conundrum

[cmacf1]

Five of us are flying BWI to MCO in mid January2008. I just went onto Kayak.com and saw that Airtran has round trip fares (taxes included) for $185. SInce I've never done ding fares with SWA (though I just signed up,) I don't know whether we should wait for SWA and hope for better ding fares or just go ahead and buy the airtran tickets. The problem is that I think we'll be on vacation in August when the regular sw fares come out and out of the country in november when ding fares might come out. any suggestions????? I'm so confused!!!!!!