I suggest you go online to the NZ Customs, & Land Transport, websites, for regulatory info on importation of a vehicle, & glean from there likely costs for fee(s) & taxes as may be applicable, check for fees both ends.
Quarantine is an important issue when importing anything into NZ, so expect inspection & cleaning costs.
Land Transport will provide info on cost of inspection for issue of a 'warrant of fitness' (ie. a 'roadworthy'), followed by the initial vehicle registration fee, assuming that's all to be included in your assessment.
Contact shipping agents & obtain estimates or quotes for shipping the vehicle, depending on how you want to do it eg. one vehicle in a 20' container, shared space in a 40' container, vs RORO, or whatever.
Don't forget to obtain insurance quotes as well.
Also, the vehicle may require towing/flatbed transportation to &/or from the freight depot at either or both ends depending on it's mobility or the circumstances. It's container may need to be unloaded at the depot vs having it dropped at your address, for inspection & unpacking, depending what's in it. The shipping agents will tell you what they require.
As anywhere you'll need to produce proof of unencumbered ownership. Support paperwork such as records of ownership, previous registration, money spent & vehicle value, can all be useful.
Hope that all provides you with a starting point.