A 1933 Double Eagle gold coin sold for a record-setting $18.9 million at auction in New York on Tuesday, and the world’s rarest stamp went for $8.3 million. The coin, the only 1933 Double Eagle ever allowed to be privately owned, was expected to sell for between $10 million and $15 million at the Sotheby’s auction. It was sold by shoe designer and collector Stuart Weitzman, who acquired it in 2002 for what was then a world record price of $7.6 million. The coin, with a face value of $20 and the distinctive design of an American eagle in flight one side and Liberty striding forward on the other, was the last gold coin struck for circulation in the United States. But it was never issued after President Franklin Roosevelt took the United States off the gold standard and all copies were ordered destroyed. Weitzman on Tuesday also sold a …