A mystery Microsoft mogul has been quietly assembling the priciest Palm Beach estate near Mar-a-Lago

In a string of blockbuster deals unfolding just north of Mar-a-Lago, a mystery buyer linked to Microsoft has quietly assembled what could become one of the most valuable private estates in the U.S.— a sprawling oceanfront compound in Palm Beach with an estimated price tag between $250 million and $350 million, according to reporting from The Wall Street Journal and The Real Deal.The buyer — whose identity remains unconfirmed but is widely rumored to be Microsoft billionaire Charles Simonyi — has spent the past several months scooping up prime properties on North Ocean Boulevard.According to the Journal, the buyer paid roughly $250 million across four separate deals, while The Real Deal pegs the total value closer to $350 million.The core of the assemblage comprises two rare oceanfront lots at 1063 and 1071 N.

Ocean Blvd., previously owned by cosmetics heir William Lauder.Together, the 2.3-acre parcels offer 360 feet of beach frontage.

Lauder, who initially intended to keep the land for personal use, had listed the properties for a combined $177.8 million.Sources told TRD the sale went through in February via a transfer of LLCs, rather than a deed, for more than $160 million.In June, the same buyer picked up two non-oceanfront homes across the street in separate off-market transactions.

A Delaware entity called Creekshore LLC acquired a 3,600-square-foot home at 1066 N.Ocean Blvd.

from former Hearst executive Cathie Black and her husband, attorney Thomas Harvey, for $18 million.The couple had bought the property for $4.2 million in 2018.In an email to the Journal, Harvey said he did not know the “true identity of the buyer,” adding that the offer was unsolicited.Next door, another Delaware LLC named Mango Leaf paid $30 million for a 5,800-square-foot home at 1072 N.Ocean Blvd., which last sold for $5.3 million in 2017.

Both sale prices far exceeded market value, local brokers told the Journal.Altogether, the assemblage now spans nearly 4.2 acres.If co...