The alternative is to take a 'jig-saw' route. Which is to put the route together using a couple of carriers. The problem with this is paying multiple departure/arrival taxes and that can really push the price up.
I am presuming that you have tried all the usual online agencies and consolidators? There are some very good ones and there is also the old fashioned way - of going into one of those that specialises in OZ/NZ and leaning on the counter. The person is likely to be on commission and you may get some options not available to the retail customer online.