What duties and taxes will be applied to the goods I have purchased from the internet when they arrive?
Low value consignments up to AU$1,000 are imported free of Customs duty and taxes.Consignments of alcohol and tobacco products are excluded from this and will be charged Customs duty and taxes.
Consignments valued over AUD $1000 will be assessed for Customs duty and taxes. Duty rates vary from 0% to 10%, however most goods attract a 5% rate of import duty and 10% Goods and Services Tax (GST).
The import duty would be paid on Customs Value (actual price paid for the goods)
GST of 10% is calculated as follows:-
Actual price paid for the goods
Plus the cost of freight and insurance
You can find more information over at the Australian Customs website.