Bad news for folks expecting that the airline will show you the best fare when you search for a city pair which requires a connecting flight. American is playing fast and loose with some segment logic in certain markets, forcing a higher fare class on the exact same flights if you search A-C (and routing you via B) but allowing a lower fare if you search A-B+B-C. LGA-AUS: LGA-ATL+ATL-AUS: Note that this is NOT an end-on-end fare issue. In both cases it is a single fare component. Oh, and delta.com generally won't sell you the cheaper fare, though it will find it on the search results if you force multi-city. Orbitz has been pretty reliable in allowing the booking to go through in my testing. Yes, it is married segment logic, but they're implementing it badly and you may be paying more than you need to for a flight...a lot more based on some of the searches I've done.