I'd suggest your thread title is deceptive as the price is not really "trippling" per pax. It's really only about 40% more per pax. A search on aa.com indeed shows there is only one seat left in the G bucket on the 5:00AM and 7:50AM outbound flights which I'm guessing what you are looking at. Attempting to book more than one seat pushes you into V fares. When booking multiple tickets together, airlines will not let you book one ticket in one fare class and the second ticket in another. They both have to be V's. That's the way ticket pricing has always worked. There is still more than 1 seat available in the G bucket on the 9:45AM flight which would maintain the $337 price per pax.