Originally Posted by
eponymous_coward
Airport taxes and fees for HK are in HKD, any fluctuations in exchange rate for USD show up in a rebate. Seen this many times for cancelled bookings involving HKD, THB, EUR, GBP…
But HKD and USD is pegged at a very very very narrow range, like the 3rd decimal point. You can almost consider it as a Fixed Rate. Even a USD10,000 wire transfer from HKD the difference in the exchange rate is less than $10 difference on different dates, different quarter. That is a 0.1% difference. At $169, that would mean 0.169 to 0.20 difference if there is one.
Now you mentioned the exchange rate, it would most likely the AUD portion because the itinerary had HKG-BNE in it.