According to Australian Frequent Flyer the trick is to avoid the “Australia tax” by buying tickets overseas.
"Most airlines charge a premium on tickets purchased from Australia. But return Business class tickets from Asia to Europe cost just a fraction of the price. By buying tickets from Asia, then supplementing these with paid or points bookings from Australia to Asia, you’re likely to save thousands."
The Frequent Flyer Gazette adds that It’s not uncommon to find return Business class fares from various points in Asia to Europe for just $2,000 during a good promotion.