JSH asked how you move to New Zealand. My impression is that New Zealand, similar to many other Western countries, has an immigration system that discriminates in favor of educated, young, English-speaking immigrants - which is not to say there aren't other ways in.
My general path here was (from the visa perspective): Visitor -> Worker -> Resident (where I am now) -> Permanent resident -> Citizen
You can see a list of New Zealand visas here:
https://www.immigration.govt.nz/new-zealand-visas
A few paths I'm aware of include:
Working holiday - if you're 30 or under, you can get an open work visa and come for two years, during which you can look for more permanent work.
Job offer - if you're offered a job from an accredited employer, making above NZ28 (~$17US)
Green list job offer - Green listed jobs take you straight to residency.
Student - after studying, you have the opportunity to work here.
Entrepreneur - start a business and be self-employed here for at least 6 months.
Investor - bring ~10 million US and invest it into the economy, or ~600,00 if you have a child who is a resident here.
Have family here - and have them sponsor you.
Overall, it looks like it isn't the easiest place to simply buy into and retire. For someone elderly, their best chance is to be sponsored by someone locally. On the other hand, I understand it's far easier to get into NZ at any level than it is to get into the US. A dentist might, for example, wait 10+ years to be allowed the opportunity to take a job offer in the US.