AWT:
Don't forget the export Certificate of Airworthiness (otherwise the import C of A could be quite a shock!).
Make sure your new buy is struck off the FAA register and FAA knows to inform CASA. CASA will not look at it otherwise.
Disassembly - US$3,000
Freight - 40' container these days is about US$8000
Assembly and Aust. C of A checks. A$10,000
Even with the above costs, there are quite a few bargains in the USA right now with the A$ north of US$0.80
Not many good, low time aircraft left in Aust. or NZ.....(assuming that's what you are after).
Stick to the reputable dealers in the USA. Many an Aussie buyer has been fleeced in the buy or got quite a shock during the import certification process (outstanding maintenance or out of date components).
Good Luck and enjoy.