Your suggested itinerary currently has three separate visits to LA. Why not fly directly to NYC by Qantas - change from the MEL flight to QF107 at LAX. After spending time in NY (a week is the minimum in my view), fly from JFK to SFO. Finally, drive down the coast to LA and spend some time there before flying back to MEL.
Great idea! So - we should get a one way QANTAS flight from MEL to JFK.
From JFK to SFO, what carrier should we fly?
Then a one way from LAX to MEL.
Makes total sense.
So - we use up our points on the MEL>JFK flight?
I'm sorry if I sound confused. I thought flights are cheaper if you book return. If we book one way flights, does that mean it will cost more?