When you place an order with us here in Australia, we send your goods via the best method via Air, the goods arrive at NZ and go through Customs where you will be contacted and need to pay the necessary duties.
Because you are outside of Australia then we do not need to charge the Australian GST. Our system automatically takes away this 10% when you enter your NZ address.
Import duties --> we DO NOT cover any duties or costs associated with NZ customs or other agencies.
We suggest you read this link for more information