Clare, there are ways of avoiding customs, but in most cases you will end up paying the import taxes. As far as I know of Australian traxation system, the import taxed includes also the shipping cost. So unfortunately it is nearly unavoidable to pay after your overseas purchases. Yes, you can ask the seller:
- To declare it as a gift (in this case you shouldn't pay GST? this is how it works in Italy)
- To declare a lower value - that's a problem if it is a pricey item and you want it insured
- To send it through untracked air mail (these items seem to get scanned less at the customs, so sometimes they get through without being taxed.
Of course, these are all gambles. If the seller sends you the parcel insured for full value, or maybe through a courier like UPS or DHL, the chance of getting taxed is very very high. There are some glitches, but you cannot rely on them.
Here, in Italy, some particular categories of products get also taxed for their nature: chemicals (soaps, bath oils, perfumes, etc.) and leather accessories, for example.