Of those, 2310 were in Auckland, a 43 per cent jump on 2011. Most sales were within the old Auckland City Council boundaries which take in Herne Bay, Ponsonby, Grey Lynn, Remuera, Epsom and Newmarket.
Wellington had just 143 million-dollar sales last year. Like several other New Zealand cities or towns, the capital had a decrease - 3 per cent - in the number of million-dollar sales. However, Christchurch's 87 sales were a 27 per cent jump on the 58 in 2011.
REINZ chief executive Helen O'Sullivan said the country's biggest cities faced lack of supply, which had driven up prices.
"I think what the data illustrates is ... the two-step market we're seeing in the New Zealand housing market.
"Where supply is significantly constrained we are seeing significant price increases and in the rest of the country it's either flat or in some cases there are declines."
In Auckland, house-hunters knew their money would stretch to three or four bedrooms but nowhere near "palatial mansions", she said.
Sales weren't confined to the upmarket suburbs but the southern part of the city was still taking longer to attract the same price rises.
"Until something changes in terms of supply I really can't see anything other than increases in prices in the region," she said.
Demand from Cantabrians wanting to stay in Christchurch was pushing prices up, Ms O'Sullivan said.
"Either buyers have got proceeds to spend from insurance or they've moved out of damaged areas into those that are perceived as lower risk.
"One thing we're seeing is a real displacement effect," she said.
"Places like Rangiora, where potentially you can commute but it's not perceived as unstable seismically, those places have seen real uplift in terms of the number of transactions and the value of transactions as well."
Last year a string of Auckland homes sold well above council valuation. In September, Auckland businessman Grant Nola and his former Bulgarian tennis pro wife Pavlina sold their bungalow on William Denny Ave in Westmere for $2.25 million - $350,000 above its council valuation of $1.9 million. They bought it three years earlier for $932,000.
In July, a three-double bedroom bungalow at 25 Monaghan Ave in Mt Albert fetched $1,086,000 - $416,000 or 62 per cent above its valuation of $670,000.
In May, a relatively unmodified former state house in Orakei sold for $1.45 million - 45 per cent above its rating valuation - and a $1 million home at 6 Bishop St in Epsom sold for $1.73 million.
In April, 30 Aratonga Ave in Greenlane, which had a $1.4 million valuation, fetched $1.9 million.