This article gives you an idea about the process of buying a house in NZ and one of the sentences says " Unless the market is red hot it is normal to offer less than the asking price.
www.enz.org/buying-a-house-in-new-zealand.html
Obviously if several people are after one house then you may well have to pay more than the asking price. Very good houses in New Zealand are snapped up very quickly and you may have to pay a bit more but houses that have been hanging around a bit usually an offer will be accepted.Obviously you need to get any house checked out by an expert.
Hope this helps
Dave and Caroline