> Unlike shopping at retail stores or Costco, bulk discounts are unusual for airlines – at least not just for booking just two passengers instead of one. And these higher fares for one passenger are the opposite of what we typically see, where travelers booking for two passengers or more wind up getting charged more per person than a single passenger.
This isn't strictly true. Airlines have long offered bulk pricing through travel agencies and booking partners.
This was prevalent until the early 2000s, it is far less common today. Corporate discounts used to exist based on guaranteed minimum legs in some time period. This ended when airlines discovered only flying full planes made them more money, making bulk discounts more pain that they were worth.
This isn't strictly true. Airlines have long offered bulk pricing through travel agencies and booking partners.