21k Oz isn't much, that's only about 8.5k Pounds. I'm surprised they're cheaper in Oz than NZ. Still more than that for a good one here. Probably nearer to 26-30k or more, depending on year of course.
As you would know from past trips, stacks of Holdens over there. Comparative would be a Monaro or a GTO, bit older than a Zed though. Or HSV, but then goes up a bit for the tag. They go pretty well, just not quite the same driving experience as a Zed. Backup servicing is pretty good, and they're pretty good with recalls this end of the world with Holdens.