When I was a travel agent, fares between hubs were among the highest! For example, AA would price ORD-DFW around $900 in Y class back in the day, while TWA might flyit for $269 Y if you didn't mind changing planes at STL. We had some very sneaky ways around it at the time then the carriers came up with ways to catch us and preclude us from getting a cheaper nonstop between hubs. We would book ORD-DFW-SAT as a one way and write one ticket for that at about $239, and then pax would just not show up for the 2nd leg. It got trickier on the return though, because ticket counter personnel were getting hip the carry-on luggage. Finally software came out detect this practice (called "hidden city" ticketing) and we had to stop doing it or risk the agency being charged for the remainder of the correct fare. The agency was always responsible for those actions and making sure the correct, published fare was used for the route. (By the way, these were all "walk-up" fares I'm talkin about).