Well, that didn't last long. We pointed out last week that you could order the iPhone 5 from Kogan for $100 less than Apple's list price, but it looks like that batch has sold out and the price has gone up slightly for new orders.
As I write this, Kogan is now listing the 16GB iPhone 5 for $749, the 32GB for $849 and the 64GB for $949. That's still $50 cheaper than Apple's list price, but you also have to factor in postage (typically around $20 for capital cities). It's self-evidently a second batch of phones, since both the black and white models are on sale this time.
The Kogan offer remains around $30 cheaper than Apple once you include postage, but won't ship until September 28. Note that customers who ordered in the first batch should still get the quoted $100-off price; it just isn't available for any newer buyers. Thanks Jak for pointing out the change!