All good generic observations about codeshare agreements, but AIRNZ does have a track record of ripping off its NZ based customers, particularly on flights to North America (it has a virtual monopoly). As an example it is always cheaper to fly from Oz east coast cities (MEL/SYD/BNE) to North America than from AKL - despite the fact that all of these transit through AKL. As an example, it is often around 30-40% cheaper for BC from MEL/SYD to LAX (via AKL) than for AKL-LAX - usually ends up similar to the PE fare from AKL once you take the extra airpoints into account. For FF who travel trans-tasman a lot its easy to book the Oz-AKL leg with a long (i.e days/weeks) layover in AKL at no extra charge - the same can be done on return and the AKL-OZ leg forfeited or used for another Oz trip. You just have to use the multi-trip booking function on the airnewzealand.com.au website.