Once you arrive in one of the main cities like Auckland or Christchurch their public transportation from the airport can get you anywhere at a reasonable price ($4 USD). The four modes of transportation I saw used were camper vans, rental cars, buses, or the train. Here are the options based on price
- Camper Van Rental $57 USD/day no insurance
- Rental Car $30 USD/day no insurance
- Train Christchurch to Greymouth $155 USD
- Bus Pass $320 USD/ for 60 hours.
If trying to have the full experience of the island while here on vacation I would recommend the camper van or a rental car. Yes, they drive on the left side of the road so just remember when pulling out of a parking lot to stay left. A bus and train will be to slow and not get you to nearly enough places you want to be.