Note: It says out of stock if you're not using a VPN or are signed into a NZ Steam account.
The official Steam website has Steam Decks on sale. 10% off of the cheapest (64gb) model, up to 20% off of the high end (512gb) model.
This means the cheapest model is $359.10 USD, which after bank fees cost me $605 NZD.
You can't purchase directly in NZ, so I used an American VPN and created a USA Steam Account. I am having it sent to YouShop, who estimate it will cost $190 NZD to deliver from the states to my door here in NZ. All up this will have a total cost of $795 for the base model, cheaper than any other deal I've seen. (MightyApe have it listed for $1200)
My plan is to manually upgrade the SSD, but if you want to take advantage of that larger discount on the high-end model, the 512gb version will set you back $519.20 USD so Approx. $860 Kiwi + $190 shipping = Approx. $1050 NZD - still significantly cheaper than a local reseller
EDIT: For the high end model shipping will be slightly higher due to more tax so total cost closer to $1085 ish
Price may vary depending on the true YouShop cost. I will update this post once it arrives there (though the sale may be over then, as Steam has said 1-2 weeks to ship). So that is a risk you are taking on. I entered dimensions and weight found online into their cost estimator to come to this price, however shipping could potentially end up being higher (or lower) if the info I found was wrong.
Does the YouShop estimate include GST?