I was trying to book a flight last night but was having credit card issues(long story) and went to book them just now and they are at totally different prices now. Do they change daily or did I miss the boat? It was through Delta. We have enough frequent flier miles for 1 free flight and will need to buy 2 more seats and the times we wanted went up $48 a seat. WTH! Are there days that they lower them and then days that htey are higher?