The practice of airlines offering cheap last-minute flights is not as common as one might think. While it seems logical that airlines would lower prices to fill empty seats, the reality is more complex.
Airlines employ dynamic pricing strategies to maximize revenue by charging different prices for tickets on the same flight. This approach allows them to extract the maximum price passengers are willing to pay. The phenomenon of passengers sitting next to each other having paid different amounts is often due to various factors influencing ticket pricing.
Interestingly, airlines tend to increase ticket prices as departure dates approach rather than offer discounts. A clear example is a Delta Air Lines flight from New York's JFK Airport to London Heathrow, where a last-minute ticket can cost around $700 compared to $200 when booked in advance.