You will get different views from different people in respect of this one.
Pitfalls are as follows;
If you are importing gear from overseas, customes may not clear your goods without having you first pay any relevant GST.
GST will be calculated on the invoice amount, (including the shipping).
Servicability; although some of the gear you buy from overseas is the same as what you may be able to purchase in New Zealand, a number of resellers of equipment have the ability by serial number or other method, determine where the goods were supplied, and i have on occasion met resistance to repair or maintain equipment purchased through a non NZ Wholesaler / reseller.
Differences in models.
Many manufacturers change their goods from year to year, with subtle improvements or enhancements, and some models never get imported into the country.
These changes and differences may mean that equipment that is not commonly imported does not carry the same warranties and parts may not be held by a local re-seller / service agent.
Be sure to check the international warranties, as some of the warranties may be international, however the wording may say 'return to base' meaning that you have to pay to freight the goods back to the supplier, who in turn will freight them back to the manufacturer.
(are you prepared to have no dive gear for an extended period of time??).
If you think that NZ Pricing is too expensive, take the Quote to the NZ retailler and ask them to 'match or better' the price.
But be reasonable, add the gst to the price, and allow 5% as a 'wait' factor, and see if the retailler 'comes to the party'.
so at 'buy exchange rates' the above landed could be..
exchange (buy) rate 0.79
=1625.35 + GST ($243.80 - you almost certainly be hit with this)
add 5% for trouble (and servicability)
I cant think of anything more relaxing, than being in the downunder, breathing some nice clean fresh filtered 21% nitrox.