Behind the big tickets: Mike Wallace’s Park Ave. pad for sale; Rothschild mansion sold; former Calvin Klein duplex on the market again; Rockets owner pays $42 mil for Gramercy condo.

$20 million: Mike Wallace’s Park Avenue duplex for sale. The home of late “60 Minutes” journalist Mike Wallace is on the market for $20 million. The four-bedroom co-op at 730 Park Avenue spans the 15th and 16th floors of the building and features high ceilings, several large terraces, a 20-foot gallery and a 33-foot living room with a wood-burning fireplace (Business Insider).

$25 million: Metalworks magnate buys Rothschild manse. Leroy Schecter, 85-year-old owner of Marino/Ware Industries, just purchased the historic 83-year-old estate–built by Baron Walter Rothschild of the Rothschild banking dynasty–at 41 East 70th Street. The 11,256-square-foot, six-story home has been on the market since 2004; Woody Allen once considered buying it. Schecter’s two-for-one combo apartment at 15 Central Park West is currently on the market for an even bigger-deal $95 million (NYPost).

$35 million: Former Calvin Klein, David Geffen home hits the market, again. An Upper West Side penthouse at 55 Central Park West that was once home to Calvin Klein and, later, music mogul David Geffen is on the market again. Neither notable spent much time at the 5,000-square-foot park-fronting apartment in the impressive, iconic Art Deco building, and its current owner, music industry exec and social networking entrepreneur Steven Gottlieb, had previously attempted to sell it for $36 million in 2008. Gottlieb purchased the apartment in 1999 for $8.6 million. A highlight of the stunning duplex: a glass-walled pavilion and glass-topped conservatory opening into a 1,000-square-foot wraparound terrace with park and city views (RealEstalker).

$42 Million: Houston Rockets owner buys Gramercy Park penthouse. Houston Rockets owner Leslie Alexander is the buyer behind the recent big-ticket sale of a penthouse at 18 Gramercy Park. The five-bedroom duplex condo in a new development built by Arthur and William Lie Zeckendorf (15 Central Park West) features four terraces and a pool. No stranger to eight figures, Alexander recently sold his penthouse at downtown condo Superior Ink at 100 West 12th Street for $31.5 million (NYPost).