Just to follow on from Richelle,
It may seem like a good idea to drop ship from outside of Australia to save on the GST, however I can only imagine most of the products you would be selling would come in under the 1K limit, and you would also need to consider delivery times to your customers.
It may well be that you have to use an international source for your products as one in Australia may not be available, however if one is, then you should take a look at the comparison across the board.