Galaxy S3 4G + free flip cover with code shipped for $492.80 from Unique Mobiles
See here for the relevant discount code: http://www.buckscoop.com.au/coupons-and-vouchers/uniquemobiles.com.au
When comparing the handset alone, Bexectech had it going for $538.95 while Harvey Norman and MobiCity are both charging upward of $570 (incl. delivery). However, Kogan was a close match on price at $498 with shipping.
The best price for this handset though was from DWI at $481 including delivery. However, when I factored in the cost of the flip cover as well (of which its market value looks to be about $25) then Unique Mobiles has the best offer around for these two items.
The deal is only valid until midnight on Tuesday the 9th of July.