Natalie Portman’s 1954 red vintage Christian Dior Oscar gown has already sold for $50,000. An unknown British couture collector in London paid for the size 4, strapless, black polka-dotted dress on 1stdibs.com. Portman presented the Academy Award for Best Actor to “The Artist” star Jean Dujardin in the outfit. The actress, the face of Dior Cherie perfume, borrowed the dress from couture dealer Rare Vintage, which then sold it on the Web site.