Retailer H&M marked its collaboration with Maison Martin Margiela with a splashy, celeb-filled bash in October, with Kanye West, Julianne Moore, Sarah Jessica Parker and others in attendance. But buzz didn’t translate into sales. Insiders have said the collection has been tanking, with what’s left of it is currently on sale at most stores. Some blamed higher prices for the goods — up to $399 for the drapey, asymmetrically shaped pieces, compared to $100 or less for most H&M apparel. H&M also produced more Margiela for H&M wares compared to past collaborations, after customers complained about inventory selling out too quickly. But others believe the fashion-forward look just didn’t translate to mass-market shoppers. A spokesman for H&M said the mass retailer was “very happy by [its] customers’ positive response,” adding: “[Our] philosophy is to provide fashion for everyone at affordable prices. For Margiela, H&M offered this collection in larger volume . . . ”