I agree with
Dave Noble and found that the additional Max, costs are not consistent. eg. on different flights WLG-AKL it was either $140, $150 or $160, possibly varied based on the base fare eg. $89 vs $69.
What I did notice was that NZ JQ has considerably gone up fro $199 JetFlex to about $229 Starter Max.
NZ Flex tickets can be the same price for a better product.
Just to add to get same product with 20kg Checked In baggage $10 so JQ just upped their fares by 20%. Not happy and this will bring NZ back into the picture for me.