If holiday travelers on the same plane compare what they paid to fly, they're likely to find quite a spread, depending on when they bought their tickets.
Fares for travel around the holidays have been rising since late summer. Christmas fares are now running 4 percent below a year ago, and the gap is likely to disappear soon.
Contrast that with a year ago, when the airlines essentially put the holiday travel season on sale. With the recession in full force, airlines used discounting to fill seats.
People who waited to book holiday fares last year saved money. This year, holding off could cost you.
Most carriers pushed through a $10 fare increase at the end of October. For the holidays, the big airlines added a $20 surcharge each way on popular travel days closest to Christmas and New Year's.
Tom Parsons of BestFares.com compared holiday fares purchased on July 1 with the same itinerary booked on Nov. 2. Several had risen 50 percent or more. Los Angeles to Fort Lauderdale, Fla., had more than doubled to $528.
Average Thanksgiving fares are up 2 percent to $351, according to Bing Travel, the fare-watching Web site owned by Microsoft. The average Christmas fare is around $370 round-trip, slightly below a year ago.
Thanksgiving fares "are up quite a bit even from where they were at the beginning of October," said Joel Grus, who tracks fares for Bing Travel. He also thinks Christmas fares will soon be at last year's levels.
Some other things to consider this holiday travel season:
* During the past year, airlines began charging $5 more each way if you pay your baggage fee at the airport instead of online.
Most airlines now charge $15 to $20 to check your first bag and $25 to $30 for the second.
* Airlines have reduced the amount of flying they're doing. That could make it tougher to buy a seat on the flight you want.
* You may get there on time this year. Fewer flights means less congestion in the air. Airlines arrived on time for 79 percent of their flights through the first eight months of the year.