He might be kryptonite to Democrats, but President Obama is pure gold to autograph collectors. For the first time since taking office, a handwritten Obama letter has come on the market, and Bill Panagopulos, president of Alexander Autographs, thinks it will fetch $15,000. In the letter to a family, Obama expresses confidence that the nation's economy will improve. Why so much? "With the advent of the autopen machine, authentically signed presidential letters and documents have become incredible rarities," says Panagopulos.