Lots of paperwork....Lots to do and many traps. Buy the plane, then it has to be deregistered in the US and reregistered in Aus, lots of customs bits and pieces. Then its in the box and on its way. Some say you need an export CofA - but actually you dont. The boxes get thrown around a bit and so you really need someone who knows what they are doing with the packing to avoid damage. Then it arrives here and the problems really start. Fisrtly you have to pay the GST and all of the other customs and handling rip-offs. Then you have good old AQIS who will probaly insist the box is opened and unpacked in a secure quarantined facility. They are particulaly concerned about timber and other packing materials. You don't know who could end up unpacking your pride and joy if they make you do that. Once you get all of your parts, after they made sure they are completely free of grisley bears and the like, your problems really really start. You then get into CASA territory because you need and Australain C of A. Most LAME's can prepare your plane for this - largely a paperwork exercise, preparing new logs, log book statement, making sure all A/D's and other Australian requirements etc are complied with. Make sure you have the full maintenance history from the US, including all 337's and other FAA records, particularly if your aircraft has any modifications, even under STCs. (You can order some of this for your specific aircraft from the FAA website) If there is any not properly documented damage history, you are in major strife. Beware here because most FAA Part 91 maintained aircraft do not comply with the manufacturers maintenance manual (not that they do here under CASA regs either) but if your friendly CASA inspector insists that the aircraft should, you may have a lot of catching up to do - and expense if you need to replace hoses, contol cables, flap motors, vac pumps fuel pumps etc etc (all of which of course were perfectly serviceable under the FAA scheme.) Then its just a 100hrly and you fly away.
Sooo, its not straightforward, it always costs more than you think and be very careful with 'cheap' aircraft you find in the US. Even with the high A$ and low US$, its still touch and go whether you end up with an aircraft that is worth more than an equivalentt one you could have bought here but there certainly is a much better selection of low time used aircarft over there - and a lot of junk to get conned with too. Mine took 4 months all up and I have quite a nice plane now but it was not really worth it in aggro or financial costs - which were 'substantial' - probably in the order of A$30K on a plane that I bought for about US$100K - and a lot of 'emotional' energy.