"Australia is a lucky country run mainly by second rate people who share its luck. It lives on other people's ideas, and, although its ordinary people are adaptable, most of its leaders (in all fields) so lack curiosity about the events that surround them that they are often taken by surprise." -- Donald Horne
At least they clearly know. Compare to frustrations with shipping from US to Europe where you'll never know till checkout whether delivery is possible or not.
The move is a response to a new GST policy that will apply 10% tax to all overseas purchases under $1,000 announced by the Turnbull government last year in a bid to “level the playing field” between Australian and overseas retailers.