During the boom's peak, one company made more than 70 such trades, with an average $86,000 gain. Dozens did the same, largely through small property investment businesses devised to cash in on huge windfalls in runaway property market.
While Buffett's reference to "others" was most likely other investors, it's clear the more fearful the vendor, the more profit.
A Weekend Herald investigation into professional property speculation examined in-depth data for the 10 most prolific traders and found the average gain on those traders' flips was $68,000, and the average sale time just 71 days.
Over six years, estimates show the 10 biggest operators made 763 such sales, pocketing about $50 million between them. It's not known how much was spent on renovation costs or agent fees.
Data revealed the flippers primarily targeted two main markets. Around half focused on apartments in central Auckland, frequently buying from and selling to investors, including many foreign buyers - fearful in a strange land, perhaps.
The other half operated in lower-value suburbs such as Clendon in South Auckland, Wellington's Upper Hutt, Nawton in Hamilton and Linwood in Christchurch. Vendors in those sales were more likely to be owner-occupiers, analysis showed.
South Auckland was the prime area. At its peak in 2015, almost 9 per cent of Manukau sales were flips. By comparison, flips on the city's North Shore were only 2.6 per cent of transactions.
CoreLogic senior analyst Nick Goodall notes the cynical element to the way some speculators focused on South Auckland as those in low-income areas were considered naive about the value of their homes, or sometimes deemed more desperate (or fearful) to make a sale.
"That's preying on people's education in terms of how the property market works," Goodall said. "It doesn't feel right, it's immoral behaviour." One might argue it's actually amoral - without regard for morality.
Former Property Institute boss and OneRoof property commentator Ashley Church says: "There was a group of flippers in the market who simply bought, sat on the property, and waited for the market to rise."
These houses were desperately needed homes at the affordable end of the market.
"They're not adding anything, just using it as an opportunity to make a dollar. As far as I'm concerned, that's a blight on society. I might be a bit old fashioned but in my opinion it's morally despicable."
Owners told our investigating journalist they felt pressured, confused, or like they had limited options. Greed feeding on those most in need. Dreadful.