Liz...I know what you mean...the prices are awful!
As far as planes filling up....a lot people take the same chance with airfare that they do with getting a hotel room. They book NOW because that is the flight they want, and hope that the fares come down. If you book airfare thru a good travel service, they watch the fares for you, and when they go down, they rebook. Of course, there is no refund, just a voucher for a future flight. While this certainly won't help current cash flow, that credit could be used for your next trip.
Makes it tough to know what to do! GOod luck!