Under $800, as low as $765 for two-week trips, on and off availablilty from this month through February. Sydney and Melbourne from Orlando. I doubt that a Melbourne-Melbourne fare is worth looking for. Look for prices on Google Flights. I'm seeing deals from United, American, Delta. You can fly direct from Houston to/from Sydney.

Maybe even lower tonight (Sunday). Try Orlando-Melbourne, Tampa-Sydney. I actually found a Melbourne-Melbourne round trip for $691. Delta.

Edited: 02/03/2019 at 10:05 PM by ww