Q. Why should Australians pay an Australian company in $US?
Answer: You're not.
You're paying AUD$ to an AUD company through a USD payment gateway.
If the pricing was in AUD, it would be much higher than the USD amount.
Prior to changing over to this model (almost 3 years ago), international users would see the higher AUD amount and many would mentally calculate that as a USD amount (not understanding, like Aussies do, the current exchange rate which appears on our TV news every night).
I also wouldn't worry about projected rates - if they were predictable, no-one would need to work for a living, just hit the Forex trade market based upon those projections
So basically what your saying is For an Australian game made in Australia and we living in Australia have to put up with payments shown in a foreign currency
because people from overseas don't understand exchange rates.
Maybe they should realize there not the only country in the world and the only currency that exists
I wonder if the US or any other country would advertise there products in AUD to keep us happy. I don't think so.