So how much does the DSi cost on our islands? NZD$400. That's how much.
Let's compare this price with the rest of the world:
United States USD$170 about NZD$274
United Kingdom GBP 150 about NZD$384.65
Japan Yen 18900 about NZD$321.40
Australia AUD$300 about NZD$378.27
That's pretty expensive. How about the DSi points? They don't sell 1000 Nintendo point cards here (same with Japan) so I'm just going to double the amount. 2000 points here cost NZD$60.
United States USD$20 about NZD$32.23
United Kingdom GBP 20 about NZD$51.28
Japan Yen 2000 about NZD$34
Australia AUD$35 about NZD$44.13
That is a pretty big investment and it's not including the peripherals (screen protector, cover etc.) which could set you back about $40-$50. If you're really keen on buying a DSi then I would recommend you import the US set. It's system and points are cheaper and you get the chance to play the newly released games without waiting for the EU to translate em.
(Exchange rates are based on Yahoo! Finance figures and are approximated)
Wikipedia Nintendo Points
Mighty Ape NZ Wii/DSi points card