Whats involved in importing a homebuilt from the states? I'm one of those that would love a small aerobatic homebuilt but prefer to fly rather than build.
How hard are they to get on the VH register?
You'll need to have it inspected and put into GA experimental and you'll be up for a LAME to maintain it from there-on. If it's well built and you know a good reliable LAME you're in luck.
I know of someone though who recently brought in a Pitts from the US based on emailed photos and no personal inspection. He has spent more than the purchase price again on repairs. He couldn't have got it registered otherwise as nobody would have signed it off.
Duty is the least of your worries as Tail Wheel says, it's the GST that kills plus the other crap.
I almost purchased a boat from the BVI's recently and I imagine purchsing an aircraft also has similar hidden costs. Purchase price + GST 10% + Duty 5%, customs broker $900, refrigerant import licence $500, registration $800'ish, termite inspection up to $900. I would have also had to pay GST and duty on the cost of getting it here from the last port, so fuel & provisions from Noumea - 10% of that. Not a huge cost but more of a money grab.