Last month, Herald Homes reported the couple selling the house were Denise Pollard, a former estate agent, and Marc Firman, director of Laser Plumbing East Tamaki.
Over 13 years, they had transformed a "pleasant but tired bungalow" for modern family living and entertaining.
They had bought another property only a few streets away and planned to remove the house on it and build their dream home.
The Raumati Rd property's July 2014 council CV for rating purposes was $1.59 million, including $1.15 million for land value of the 663sq m site and improvements of $440,000.
Ms Walton said all the prospective buyers disregarded the CV as an indicator of the property's true value.
"The council CV did not reflect the value because CVs adjust when there has been a sale and this home had not sold for over 10 years."
The Herald last month reported wide discrepancies had been revealed between the CVs and selling price of some homes, with some industry experts questioning the accuracy and relevance of new valuation notices.