So what are the add ons? We have AC's own fuel surcharge, which just about every other carrier has also adopted, adding C$19 a flight, or C$38 on the return. There is no Cdn GST, just the Aussie version. [I think you pay it even on overseas flights, we don't here in Canada when we fly outside the country.] Then there's the US immigration/customs/ag fee of around A$50, and I think Australia levies a similar charge. Canada does not. Then each airport has its own AIF, again nothing to do with AC. And if you're collect AE miles, then the SYD-HNL will earn a nice 10K or so, which sets AC back a C$100 or more as it is paying AE for those miles from the meagre A$350 [about C$320].

I am not sure AC is even making a profit on these fares, just topping up the flight and filling seats that otherwise would have gone empty. This fare is cheaper than the lowest TANGO+ fare between YEG-YYZ return and earns 3x the mileage. Quite a deal, and the only gougers are the various non-Canadian governments who are taking money out of the pockets of travellers.