Once upon a time, the Australian dollar was worth about 50 US cents, so things in Australia cost about double what it cost in the US. Then the Australian economy started booming, and now the AUD is stronger than the USD. But everyone who sells stuff in Australia thought "wait a minute, these guys are used to paying double, so what incentive do we have to change?".
So now you have retarded pricing, like some places expecting you to pay $110 US dollars for a single video game. Don't even get me started on the price of food. Unless Australian retailers change their tactics, they will slowly go out of business, because an entire generation of computer literate people realize you can get 2-3x more out of your money just by buying from online stores.