What do you get when you cross Robert A.M. Stern’s architectural vision with the muscle from Zeckendorf Development? You get 520 Park Ave., the 54-story limestone-clad power tower that has redefined not only the East Side horizon, but the NYC record book for most-expensive apartment sales. Coming in at $73.8M, this 6-bedroom, 9,000 square-foot penthouse was purchased by none other than James Dyson, the vacuum cleaner inventor. Talk about cleaning up!

After sales commenced in September for 520 Park, the 800-foot limestone tower started seeing buyers close on some of its 34 residences. The second-highest priced apartment in NYC in 2018 was purchased by investment banker Ken Moelis, who took command of a 9,200-square-foot duplex for $62 million. Just a little chump change for this billionaire.

A penthouse duplex at the uber-exclusive Getty in West Chelsea was not big enough for private equity firm founder Robert Smith, so the engineer-turned-financier tacked on another unit located below the duplex, then settled on the deal for $59 million. This luxury building on W. 24th overlooks the High Line was designed by superstar architect Peter Marino.

A stunning makeover for this full-floor residence high atop One57 helped seal the deal for this $53.9 million sale. But in a sign of NYC’s slowing luxury market, this 85th-floor penthouse did not fetch close to the original list price of $70 million by Canadian billionaire Lawrence Stroll. So, we guess that makes this modern marvel a bargain?

His basketball team plays in the City of Brotherly Love, but Philadelphia 76ers team co-owner Michael Rubin scored in the Big Apple. The e-commerce exec shelled out $43.5 million for a stellar penthouse at 160 Leroy St. The 7,750-square-foot residence also boasts a 5,000-sq-ft terrace with a private pool. Swish!

Here’s another apartment deal that helps illustrate the downturn in NYC’s luxury real estate market. This 77th-floor residence closed at $42 million for an undisclosed buyer, which was a loss for the owner who first purchased the 6,240-square-foot unit in 2015 for $47.8 million. Still, that’s a lot of coin.

This $42 million penthouse was one of two units on the 77th floor (along with #77A, which sold for $22 million) at 432 Park that went under contract in 2018, sparking rumors that the pair would be combined into a massive floor-through. So far, no word on any combo renovation.

This 15,000-square-foot mansion was transformed into palatial digs by developer Joseph Chetrit, however he failed to nail the $50+ million sale price he sought, settling at $40 million. Whoever bought this beauty must be in 7th-story heaven.

Number 10 on our StreetEasy listings of the highest-priced sales for 2018 features an Upper East Side mansion with a history. Billionaire tech-king Tianqiao Chen was the buyer of this Vanderbilt Mansion, which has been owned by Libet Johnson, the Johnson & Johnson heiress who died in 2017. Chen paid $39 million, far less than $55 million list price and less than what Johnson paid ($48 million) in 2011.