Since i need to fly RT HKG-BKK i just checked Jul 10-Jul15 on Zuji.com
Air Asia came in 2906 HK$ (all in, but no luggage and only 7 kg carry on, only one flight). CX was 3384 HK$ (a few flights), Thai was 4154 HK$, also several flights available.
Just for comparison i did check HKG-NYC for the same days. Cheapest was Delta 1 stop at 9907 HK$ (one stop), JL/AA combination was 10409 via NRT, cheapest NonStop on United for 11027, CX was 11470.
Either you are looking on a US booking site o were extremely unlucky in picking the dates.