How to decide on subject like this?
First of all moving to New Zealand is often decided on many different very personal levels. There is no way to generalise how to decide on moving or which steps to take towards moving to NZ. All situations are unique and therefore have to be evaluated in their uniqueness.
Relocating to New Zealand and becoming expatriates was a quite spontaneous approach. We simply fell in love with this country while travelling, acted upon it and ended up emigrating to New Zealand. Generally I would encourage anyone who loves this country and can embrace it in all aspects to examine every possible way to make it home. There is no such place on earth that is perfect. The place simply has to be perfect for you and the needs of your family.
Sometimes this is something you know straight away and sometimes it becomes clear after a visit.
Generally New Zealanders are proud, good natured and good hearted, friendly, and helpful. Sadly this does not exempt from violent or abusive individuals, they are just people. The good thing though problems get addressed often much faster and more pronounced, hence some get the impression crime is on the rise. Personal experience taught that things you expect or believe in more likely find a reflection in life. To get an impression on what happens and what makes the country move you may want to read the counry's leading news paper the NZ Herald .
When moving to New Zealand there will be a cost of living like food prices, housing prices, cost for utilities, and transport. They depend largely on consuming habits, location, and level of comfort, personal interest, and needs. Tax and GST are also no strangers to New Zealand. Costs occur too for medical consultations and prescriptions.
Since it is an independent country some of these costs compare higher and others lower than to your country of origin. Moving to New Zealand will change your habits, hobbies, and needs because it is a different place, therefore a straight forward comparison might mislead at times.
Generally there is always a cheap way to do things and a costly way. It is as always in the hand of each consumer to decide what is acceptable to pay for which goods or services.
Therefore even if you think you get all the information together before hand there may be surprises in one way or other. What it is like you will only know when you moved, settled in, and got to know your way around.
But I understand you would like to do as much research and gather as much information as possible before making your decision. Here are some helpful government websites to research your options by yourself.
The The New Zealand Immigration & Relocation Report on the other hand gives all information neatly put together in one e-book that is researched by the NuKIwi Team with a portion of own immigrating experience.
Read relocating to New Zealand stories of other site visitors or write your own.