Peter and John Rossiter pocketed the windfall sum for their family's 118-year-old waterfront home last month.
Their forebears paid £400 for the property which remained in their hands ever since.
The house on the property has fallen into disrepair, with stained carpets and peeling wallpaper making it the ultimate fixer-upper.
At the time of going up for tender, the property had a rateable value of $2.475 million.
Property records list the purchaser as Possum P Ltd, whose sole director is Virginia Maxwell.
The new owner also appears to own two neighbouring properties. It's unclear whether she plans to knock it down or embark on an ambitious restoration project.
Maxwell could not be reached for comment today.
From the outside, the property looks like it's had a tough life. Inside, it's a step back in time.
Marketing photos showed the original furniture still in situ.
In one room, the heat burn mark from the cast iron stove stained the wall above as the discoloured and ripped wallpaper from years gone by masked the home's walls.
In another room, there was an aged piano with chair, table and recliner positioned to get prime views.
The house sits on a freehold 865sq m site and is zoned for a single dwelling but has views out over the harbour and the Harbour Bridge.
Harcourts real estate agent Cynthia Klenner wouldn't disclose the sale price but said the Rossiter brothers were pleased with the amount.
As the area was categorised as "special character" a new house would have to be "built to heritage" under the Auckland Unitary Plan or in keeping with the historical nature of the area.
"Most people would say that the house is too far gone but it's about the land and location and what [the new owner] can do with it," she said in March.
Peter Rossiter (60) earlier told the Herald he could still remember watching the clip-ons being added to the Auckland Harbour Bridge.
Rossiter lived in the house up until the end of 2016. He said it had held precious memories from over the years but it was finally time to let the property go.
