In 1910, when Harry Payne Whitney bought his father’s mansion on Fifth Avenue, The Times reported, “No house in the country, perhaps, has been more sumptuously and artistically furnished.”

Also: “The great bronze fire dogs in the dining room are the finest in America.”

It cost “a trifle under $3,000,000,” fully furnished, “the largest private house sale in respect to price that has ever been recorded in the city.” (That would be about $80 million today.)

In the modern era, the most expensive homes in the city were bought and sold at a scale that was, in a way, understandable. Prices ticked up by a million here, a couple million there.

Then things started to accelerate. By 2006, a home on East 75th Street sold for $53 million.

That record was shattered in 2012 when a penthouse on Central Park West was sold to a Russian oligarch for $88 million, soon to be topped by a $100 million sale.