Kohn Pederson Fox-designed One Jackson Square is riding high, with only three units for sale within its walls of undulating glass. But why buy when you can pay $30,000 a month in rent! #PHC, which was sold to an international buyer this summer for $4,582,125, is now up for that particular honor. (Not to be confused with #PHA, the blockbuster penthouse that finally exited the market, stage left, at the bargain price of $16.9 million.) It's got all the neccessaries: southern exposure, set-back terrace, three fireplaces, marble bathroom and so on, though no evidence of Mongolian lamb hair-covered kitchen stools.