I was tipped off that Studio Series Core class Wheelie was in stock at Amazon Australia on thursday, as someone ordered it and got it in the mail yesterday... but it is now showing as out of stock, so hopefully they restock soon. It was at their regular Core Class price of $22.
After a bit of searching I found Ratchet as well, but it is showing as US stock for $32!

Both were listed with Movie 7 (Rise of the Beasts) code names, which was why they were hard to find.