There's tons of ways of getting around New Zealand. In general it's far cheaper to book things in advanced - especially around Christmas/New Years holiday season when last-minute flights/ferries can get pretty expensive or hard to come by.
Yeah, it's all sweet. Just remember to make it clear where you want to go - and be prepared to wait around in the weather. It does help if you're a lady or a couple in getting picked up.
Generally every town/city is accessable by bus, along with all the major tourist attractions - such as national parks etc. For a cheap bus fare, nakedbus.com is the way to go.
If your budget isn't as tight as a nuns twat - getting around by car is generally the best way. Fuel will run you (as of Nov 2011) about $2.10 NZ a litre of 91 (regular). Diesel is cheaper as it isn't taxed at the pump. For latest pricings check out either AA Fuelwatch or Pricewatch.
The main supermarkets offer fuel discount vouchers, which give you between 4 and 20c per litre discount off fuel if you spend $40 or more. The voucher is printed along with your reciept, expires in a month, and can only be redeemed from the fuel station printed. Caltex will honour all vouchers.
Cars in New Zealand are cheap thanks to second-hand Japanese imports. That makes is pretty viable to simply buy a car if you're in the country for more than a couple of weeks, then sell it when you leave. Places to buy/sell include TradeMe motors (kiwi ebay equivalent), the local news paper classified section, car yard, or people will park the car on the side of the road with a number to call printed in the rear window.
- Cars can be sold with money still owed on them, which is transfered to you. Make sure to run a check on the car using the government Personal Property Securities Register (PPSR) database before buying.
- Cars in New Zealand require a valid Warrent of Fitness (WOF), and registration (rego). Registrations last for a year, WOF's on most cars are 6 months. Check the car has both.
- Before you buy a vehicle - Ministry of Consumer Affairs
- Even if you're visiting New Zealand, you can pick up a free AA Smartfuel card from BP, Caltex and AA Centres. This will help you accrue discounts on petrol.
If you plan on moving between the North and South islands you'll probably need to catch a ferry. There's two companies: Interislander and Bluebridge . Generally Bluebridge will be cheaper. Around the school holidays and Christmas/New Years, the ferries get pretty booked out and expensive. It pays to book ahead if you're travelling around then.
Domestically, there's either Jetstar orAir New Zealand. Routes between the main hubs offer the cheapest flights - Auckland, Wellington and Christchurch. Going to smaller feeder routes can cost a shitload and it's generally cheaper to bus or drive.
Jetstar have terrible service and are universally hated, but they're cheap so everyone still flies with them. Air New Zealand are fantastic, but cost more than Jetstar. However, they run a site called grabaseat which offers really cheap flights. If you can, try nab flights off there.