Apple have made some changes to their international pricing, so this means that the comics we buy change in price.
As I understand it, Comixology choose what price tier a comic is and Apple translate this across the app store to the local currency.
So a comic which used to cost 59p (the equivalent of a $0.99 comic) now cost 69p.
By all accounts, us in the UK have been doing OK out of this exchange rate, so while it leaves us a little worse off, Australia are better off with a price drop!
The Comixology blog have also clarified the situation with a handy table for you to compare and contrast
