$120 Million. Andrew Carnegie's niece was a previous owner of the 51-acre Long Island Sound waterfront compound. Named for the beautiful, lush copper trees on the grounds, the Connecticut estate with a private beach and massive 13,000-square-foot Victorian mansion hasn't advertised for a buyer in over a century. Unbelievably, $120 million was a $70 million price slash from an original ask of $190 million. Yes, nearly $200 million. David Ogilvy & Associates for Christie's International Real Estate handled the sale.