This trackball currently 1/2 the price of the cheapest AU stock (officeworks). Have been after one of these for a while but the price was prohibitive. Amazons pricing on PC stuff is incredible for us currently with the high AU dollar.
I'm going to be using this on my HTPC. These are a godsend for this sort of use.
Probably being discounted as the MX Ergo is out: Logitech MX Ergo