Living in Australia or NZ, one is inclined to pay too much if you buy store-stocked products. This is reason enough to buy online from places like http://excsur.com. This outfit served my step-sister in Australia, so I don't know if they service NZ. Ask them. There are many such online outfits. Obviously its better if they have a local office. I bought my Toshiba laptop online for $NZ560, with an extra battery from a group in Auckland called Playtech - see www.playtech.co.nz. Often you come across these groups by doing a search for popular items like computers. i.e. These wholesalers are often listed on price-comparison websites.
In Japan, I bought a GPS from another group - forget the name of that group, but they were British international. Ex??.com.
A lot of these companies offer free shipping, but of course its the total price value. There are certain things you want to buy in-store. Some things are hard to buy, like business shirts. You need to make sure you know how to measure your size by their standards. Your tailor might have different fitting standard to them.