To me this message of yours is a learning to make note of: "Plus, in Australia the listed price is the price, whereas AirBnB drags in the obnoxious American custom of tacking on extra fees right at the very end of the transaction."
When we take any service to a different country / continent, we need to take into account the local practices of the place (especially pricing) and build it into the system, wherever possible.
As an American, I can tell you that we find the practice of tacking on fees just as obnoxious as everyone else does. If you're a business extending the 'courtesy' of posting actual prices to other countries, we'd appreciate it if you'd also do it for us.
When we take any service to a different country / continent, we need to take into account the local practices of the place (especially pricing) and build it into the system, wherever possible.