Pete, we pay through the nose in Aus.
Last year, E70 prices started at $99k AUD here and only $64k USD in NYC. This is when the AUD was at the strongest 1.10 USD.
I do buy my parts from the USA and have them shipped.
When shipping tyres, check with companies that ship classic cars from the US, use their forwarding address (holding warehouse) in LA to get free shipping within the US. Some will charge as low as $25 per tyre to bring into OZ in the same container, may be a little more since these tyres are huge. Don't forget to add 10% GST.
I hope that helps.