It's capacity pricing. If you want to buy same-day tickets for your whole family to board a full flight, the airline will sell the tickets to you, but it might

It's capacity pricing. If you want to buy same-day tickets for your whole family to board a full flight, the airline will sell the tickets to you, but it might be at a 5x or 10x mark up. The airline is betting that they'll be able to talk people into forfeiting their seats by giving them airline credits, and tickets on a later (less crowded) flight, then pocket the difference. Expecting the airline to give you and your giant family a discount in the situation is obviously absurd. When you're at capacity, it's in your best interest to encourage people to shift their consumption to off-peak times, and to punitively charge the people that insist on consuming a disproportionate amount during full capacity.