For items above $1000 there may be no duty but if customs decide you need to pay GST then that isn't all you pay. If it has come via Aust Post and customs hold it up they send you a letter with a number on it for the item. You then have to fill in a declaration form- one of these
http://www.customs.gov.au/webdata/re...bleversion.pdf
You then have to find the correct code for your item from this list
http://www.customs.gov.au/tariff/tariff.asp#tariff677
They then charge you a fee for the processing as per this document.
http://www.customs.gov.au/webdata/re...es/ACN0621.pdf
I forget what I paid last time but it was about $40 on top of the GST. When this is all paid they release your item.
Cheers