Would need to check with the numbers guys online to see if VGChartz could be under tracking the Wii in Australia. Looking at the charts here it has Wii at 586k, that's a pretty big difference to the 750k reported here, around 1/3rd of an increase.
Not sure how many retail sources they have here in Oz
Never argue with idiots
They bring you down to their level and then beat you with experience