Collectible design taking its biggest ever platform at Milan design week tells us something significant about the current state of design, writes Debika Ray . Starchitects may have fallen out of favour, but the star designer is back on the ascent. What better evidence than the launch at this year's Salone del Mobile of an exhibition of "collectible design, limited editions, design antiques, and high-end creative craftsmanship"? This is the kind of design that screams "ask who created me!" Salone Raritas features exhibitors including Dutch designer Sabine Marcelis , Milanese gallery Nilufar , Dubai-based brand Collectional , Brazilian gallery Mercado Moderno , Swiss architecture firm Herzog & de Meuron and Italian glassmaker Salviati . This is not an art fair or consumer sales platform: it's aimed at Salone's existing trade audience of developers, architects and interior designers.…