Buying a Boat in New Zealand

[Boatfreak]

Hi All
I am looking to replace our catamaran with a newer, bigger boat and one has come up New Zealand. They are a bit rare so I could be a long time waiting for a European one to come to market. I am in the UK and have previously bought two foreign owned/located boats but they were both in EU countries when we too were in the EU. New Zealand is whole new ball game. We are of an age where the boat is not likely to make it back to Europe, so to get a good percentage of the purchase price back it needs to eventually be sold somewhere accessible with a good boat buying population.
The ideal plan would be explore New Zealand then head for S.E. Asia etc., but the burden of research is immense in the time available and we are not currently great crossers of oceans so would not want to be committed to an Indian Ocean passage.
I was wondering if the community could point out any pitfalls I might be about to overlook. Things I can think of are.
• Tax Liabilities
• Seaworthiness legislation
• Insurance
• Visa Limitations
• Cruising Grounds
• Possibly Vastly different cost of Ownership New Zealand to EU
• Sailing Seasons
• Storm Seasons
• Laying up issues e.g. preferred places, afloat/ashore etc.
• One Way only Passages
These are the things I have thought of, there may be others. At the moment I am just trying to decide if this is something we could get interested in. All opinions on anything relevant welcome.

Thanks