$428 Kitchenaid Artisan 5-Quart Stand Mixer KSM150PSBY with frequency converter @eBay
However, I found an American seller who sells them with a frequency converter to Australia for a great price. She sells them via ebay.
You can buy it now, but occasionally, she does list auction prices that start at $1.00 (but they tend to go for way above US$300).
I bought one from her for $370 delivered (Problem with auction listings - you don't get to pick the colours and my colour is UGLY..wish I had just bought the red outright lol)
Bear in mind that there is probably no warranty as they are for the US market.. but for that price, I was happy to take the risk. Her feedback is really good too.
I like that she includes the frequency converter.. as between you and me, I have no idea where to get one of those and am worried I might buy the wrong one and kill my expensive mixer ;(