Example: A purchase of 1 model (1/72nd scale model, i.e. Tank) 
Size of a box: 23.5cm (length) x 16.5cm (width) x 7cm (height), weight up to 3kg
Shipping location: urban
Economy: $8 (delivery: up to 3 working days)
Courier: $10 (delivery: next working day)
Signature on delivery: add $3
For rural delivery: add $5.50

For more information, please check:
 
https://www.nzpost.co.nz/personal/sending/sending-guidelines/pricing-tables