Note the word officially there. Amazon for example has a German store so if they want to sell stuff here they have to follow the local rules. Now if I order in some obscure US shop and manage to convince them to ship to Germany they aren't obligated to follow the local laws since I buy in the US.
Since I'm not aware of an Australian-based digital vendor, I can't see how local retail price maintenance laws would apply to GOG (Polish, I presume), Valve (US), GamersGate (Swedish) etc.
Those austrians is like all asians, all commies I say.