The thing about shipping internationally is that you generally need a logistics partner to actually physically move the packages for you, and they also have a legal responsibility to ensure that what they are carrying is legal. I don't know what number of packages you need to have seized by customs before they stop doing business with you, but I'd doubt it's much more than 1.
As a bonus, there are only a handful of logistics companies in NZ that do international outbound, and they are the major domestic delivery companies as well, so if you fuck around enough you could end up finding out that no one will deliver your packages locally either