Ahh I knew that travel agencies/agents offered discounts on normal fares in mainland China but didn't know that it applied to HK as well.
Even then...it still looks a bit outlandish. HKG-BKK is $741 in CX, $208 in Thai. HKG-NYC is $3431 in CX, $745 in China Eastern and $1349 in AA. Everywhere I look CX is a 300% markup. Just seems like too massive a difference, even when comparing nonstops to 1-stops at other hubs. Haven't seen anything like this with other airlines.