Originally Posted by inlanikai
Historically, it has always been cheaper to travel from the US to SIN than to NRT on AA. Not sure why, but the fare differences can be quite dramatic. Recently, JFK-SIN on AA in J (JFK-NRT-SIN r/t) was about $5400 but just go JFK-NRT (using the same AA167/168 flights) and it was over $2000 more on the same dates.
Fares are market based and not always mileage based.
Also (and especially) true in premium cabins for TPE and BKK-- much cheaper generally than NRT and HKG (even if you're connecting through one of the latter to get to one of the former.)