To some extent that's true Smithy, that is basically the way it is...but make no mistake, there's nothing overtly more noble / more commercially minded about it as far as the Kiwis are concerned. Instead it is down to the fact that most Aussies aren't sellers because, unlike the Kiwis, they simply don't have to be. To start off with the Kiwis produce well in excess of the number of horses they'll require to fill their race fields every year & due to the addition of a number of things, not the least of which are a their harsh(er) handicapping system & a general lack of racing opportunities they simply have to sell, they have no other choice but to sell. Further to this (somewhat enforced by the circumstances) selling approach is the fact that for NZ, the US/CAN market has all but dried up so at present and for the foreseeable future Australia is pretty much their SOLE market.
That's not going to inflate the prices for going stock...it's all about supply and demand (sorry Breno).
If you're concerned about prices for going horses being inflated then might I suggest you consider those fellas over in WA who have been shelling out phone numbers in order to pick off the top end of the NZ going concerns...and in doing so duly raising the expectations of price for a swag lesser lights? They're belting the prices along way, way more than any increased charges/fees could ever do.