Playmobil is apparently very decentralized and doesnt ship internationally, but luckily they seem to have branches everywhere
Switch the .com part of the link (bold below) to whatever they use in your country to find out if they're stocking it:
www.playmobil.
co.uk/roman-colosseum/6548.html
I cant find a .au Playmobil site though...
Its available in Denmark!