I have one for sale in silver at Ebay Germany, but i guess shipping to Australia doesn't make sense.Yeah, the A-S801 (which is sadly not available in Australia) has an actual USB-B input, where as the lower models only have optical and coaxial.
Anyway, if any of you guys are into buying used and you want to buy an external DAC anyway and you want to have the power amplifier shared in the A-S700,701,801 and R-N803, search for the R-S700. It's the only one of the bunch with pre-out/main-in loop, which means you can loop in a DSP/EQ or split it up and use it as a pre-amp or power-amplifier if you update later. Pre-out/main-in loop can be added to the others as well, but you have to have a soldering iron and that's not everyones cup of tea.
They can be had for 200€ or less.