Here's an example of how this will work.
A few years back I imported some goods for my business and kept the value of the goods under the $1000 threshold.
But, at time of arrival in Australia, the dollar had dropped and the value of the goods came to something like $1015. I then get a call from DHL ( the carriers) who tell me that the goods cannot come into Australia unless I pay the GST and import tax... do you want us to do this for you or do you want to deal with customs yourself?
Anyone who has ever tried to deal with customs knows that all the cards are stacked against you.. they will have you going in ever increasing circles of red tape, all the while, your goods are sitting in storage at customs which attracts a $170 daily fee.
So.. I agreed to have DHL pay the tax and I reimburse with my credit card. DHL then add on an administration fee and my bill to DHL came in at just under $400..

.. all this for $15

If you think that Aus Post..DHL...TNT etc are going to ask you simply for the 10%..think again as its a total money rort for these guys