We did the math on Ken Griffin's pied-à-terre tax bill Ken Griffin has found himself at the center of Zohran Mamdani's campaign to tax the rich. Fabrice COFFRINI / AFP via Getty Images; Lev Radin/Pacific Press/LightRocket via Getty Images New York officials rolled out the details of the city's new pied-à-terre tax this week, so we took out our calculators and got busy. The tax will impact an estimated 10,000 properties in New York City, including those of Ken Griffin , who has found himself at the center of the discourse about the levy. When Mayor Zohran Mamdani announced the tax in April, he called out Griffin by name. The Citadel CEO, who lives full-time in Miami, owns three apartments in New York City: a penthouse on Central Park South that broke records when he bought it for $240 million in 2019 and two units in the upscale Upper East Side coop 740 Park Avenue, which he spent a total of $83 million on over the past year and a half.…