It wasn't that long ago that airlines were slashing prices and offering huge seat sales to lure timid customers back onto planes during the pandemic. Safe to say, those days are over. For at least a year now, prices have been climbing and the summer travel season marks a new peak. A peak that likely won't last past next summer.How are seat prices set, anyway? How much of this is based on an airline's increased costs, and how much is a profit grab? What can you do to try to find cheaper fares? Do price-busting apps actually work? And why do you and your friend see different prices for the same seat on the same plane?GUEST: John Gradek, Faculty Lecturer in Supply Chain, Logistics, Operations and Aviation Management at McGill University