Not quite sure when you want to depart or the duration of your trip, but a 15-day LAX-SYD trip shows plenty of availability for 2 on dl.dumb:

Departures on

Oct 24
Nov 4
Jan 15
Mar 8
mar 29
Apr 5, 6, 7, 12, 13, 14, 19, 20, 21, 26, 27, 28


If you have flexbility on trip length, search O/W awards and you'll find even more inventory