Apple has an Apple Store in Australia. Just checked the prices of the cheapest MacBook Pro.
US: USD 1999.00
AU: AUD 3199.00 (about USD 2621.12)
But the Australian price includes the sales tax, so the difference would be around USD 400-500. If you include the additional shipping from the US to AU and all the taxes you have to pay, the difference would be much less.
I don't think is worth it, unless you are traveling the US, or someone you trust is coming to Australia.
You can also check for any shipping forwarding company. I use a service to receive packages from the US. They provide an address in the US, and they transport the packages received to your country. You pay the shipping plus any other charges.