serfty has put together a great DONE4 that includes Australia travel and almost maxed out, which he flew this year. Note some of his flights are seasonal. It is certainly possible to add lots of SCs and even save some nights in a hotel.

For price, it is significantly cheaper to start somewhere like CMB or BKK than to start in Australia, even after allowing for price in $ or points for award to get to & from the start and end. Even NZ has a reasonable price saving over Australia (and would be less hassle factor compared with CMB/BKK albeit less savings too).

A sample itinerary starting in SYD might be

SYD-lhr-mct-LHR-CDG-lhr-LAX-bos-dfw-anc-ord-slc-jfk-hkg-cmb-hkg-nrt-syd-adl-per-SYD

By my reckoning this earns 2330 SCs, and assuming you start as QF Gold status with no SCs earned in your membership ytd 123,000 QFF points (+ further 26,000 accrued from loyalty bonuses).