Hi Georgina, not wishing to crowd in on Rachall's posts as we think she has done a brilliant job in her posts, but just thought we would tell of our experience so far.
We are doing similar to you and have had the VIA passed and the caravan is sitting in the shippers warehouse in the UK waiting to be containerised.
The quoted cost to do this to date has been, transport to warehouse nil, as it was part of the purchase deal, marine transport $4050.00US, insurance for transport by sea $338.00AU, shippers fees from UK warehouse to Aust warehouse, dock costs, quarantine, container fees etc $1500.00AU, this amount does not include GST and customs duty that has to be added on to the combined cost of the caravan, marine transport and the insurance.
When cleared from the Aust warehouse we will arrange a tilt bed truck to pick it up and transport to a place of compliance ready for registration. In ringing around quoted costs have been approximately $250.00 for transportation.
As yet we haven't got a cost for compliance, however Rachall has given us a good ball park figure to work with.
The above info is for shipping by container, roll on roll off was $1500-$2000 extra.
There may be other costs that I am unaware of, if so, I'll update our post later on.
I realise that this may not be the same as your situation, but it might give a general estimate.