Originally Posted by
exerda
Maybe they do have discount fares on NRT-GUM and GUM-HKG, and it priced end on end?
I imagine that's what happened; while most discount UA fares prohibit end-on-end, those don't. That said, even the cheapest fares I see published add to about US$700 RT, whereas the ANA nonstop was about $550 (and HK Express is cheaper still).
There must also have been an inventory issue with the competition on that date.