As a bonafide traveller to Australia, you may be eligible to purchase many items tax free, but there are certain rules and regulations that apply.
There is the Tourist Refund Scheme (TRS), which enables you to claim a refund, subject to certain conditions, of the goods and services tax (GST) and wine equalisation tax (WET) that you pay on goods you buy in Australia.
To claim a refund you must spend $300 (GST inclusive) or more in the one store and get a single tax invoice, buy goods no more than 30 days before departure, and wear or carry the goods on board the aircraft or ship and present them along with your original tax invoice, passport and international boarding pass to a Customs Officer at a TRS facility.
Claims at airports are only available up to 30 minutes prior to the scheduled departure of your flight.
Claims at seaports should be made no earlier than 4 hours and no later than 1 hour prior to the scheduled departure time of the vessel.
The refund only applies to goods you take with you as hand luggage or wear onto the aircraft or ship when you leave Australia. It does not apply to services or goods consumed or partly consumed in Australia, such as wine, chocolate or perfume. However, unlike other tourist shopping schemes, most of the goods, such as clothing and cameras, can be used in Australia before departure.
Check with the retailer where you are purchasing to get the best up to date information relevant to their products or check online at www.customs.gov.au.