AUD has a relatively high exchange rate range against USD (the upper range is about 80% higher than the lower). When deciding price be sold to Australia that would last for some time and cannot mark price-up just because of exchange rate change, I'd probably choose a mid-way upper price level.

Although we can buy softwares through the internet, Microsoft has still need to care for local retail shops that are selling retail boxes for them, therefore cannot make the online option "too attractive".

Btw, I heard the internet connection speed was slow for most area in Australia, is that still the case there?