Xbox One + Assassin's Creed Black Flag + Assassin's Creed Unity $399.20 using C20EXTRA coupon
The redemption code requires payment with an Australian PayPal account.
EDIT: AC Black Flag is free with Xbox Live Gold this month, something to keep in mind if you are hunting for the best bundle deal. (Thanks to Toaster for the extra insight)
AC:Black Flag is free for the month of July for Gold members. Just something to take into account if purchasing this bundle :)