The great advantage of collectibles in the antiques market is that they need not be especially old nor cost a fortune to invest in. This guide by a British expert in 20th-century collectibles is packed with color photographs, prices (in pounds and dollars), dates, and makers of more than 4,000 items, including Eames chairs, Rosenthal china, art deco glass, vintage designer fashions, Beatles memorabilia, and even a Darth Vader telephone.