Thanks for the reply. That makes sense now. And do to the location of AKL in relation to Sydney, its doesn't look like I could use any creative routings to get around this, unless i travel through antarctica, haha.

The ticket I currently have is an open-jaw ending in AKL, and I'm looking at buying the one-way return to SYD, but its ridiculously expensive.

Is it possible to call up AP and maybe "put one by" the agent and get the last leg booked? Or will their booking system automatically stop them from adding on the last leg/

Thanks