Hi, I'm thinking of booking flights on SW for Feb. with the sale going on today, but wondering if I should hold out for a good Ding. But I've read posts where people have gotten better sale prices for flights they've already booked on SW and received credit. How does that work? If a better fare comes along in a Ding, would I then call the airline and request that fare (or the difference between the booked flight and the Ding fare), or would I book the Ding fare and get credit for the fare I already paid? Thanks for any light you all can shed!