On May 5, I booked MSP-BNA RT 18-22 Nov in coach. 25K miles. Kept it on hold (ticketing deadline today). I really wanted a return 2 hours earlier than the one that was available, so figured I can SDC. Well, just before ticketing today I checked again and the earlier flight is available. So I could rebook onto that flight before ticketing. Availability changes constantly! Cash price would be $400 RT.