You will NOT be charged New Zealand GST, so the prices for you will be approximately 12.5% less than the prices shown in the New Zealand store. You will also score a good win on the exchange rate, so altogether, this should offset the freight charge.
Standard Freight(all in NZ$)
Allow around 7-days for delivery
1 to 4 bottles of capsules/tablets per package: $9
5 to 8: $12 11+: $18
NutraStart and RioVida being heavier will incur higher charges