So-called couture costume designs are making a bold statement at retailWhile many fine jewelers aren’t ready to offer costume pieces alongside their diamonds and pearls, stylish women may not take no for an answer. Fashion designers have long flirted with the world of accessories, going back to the 1920s, when Coco Chanel dared to pair strands of faux pearls with her couture designs. But in the wake of this decade’s financial crisis, the idea of fine costume is becoming more attractive to women of all ­backgrounds who want to affordably, and fashionably, update their jewelry wardrobesJanet Goldman, founder of New York City–based Fragments, a hip downtown destination for emerging designers, thinks that fashion’s embrace of costume could not have come at a better time. “With the price of gold going sky-high, people are looking to other avenues of creativity and finding it in fas