Sure, it says "$10" on the corner, but a Pennsylvania collector's bill is worth far more. Billy Baeder, of Royersford, Pa., is into "fancy serial numbers" and other unusual currency characteristics collectors value: printing mistakes, for instance. Fancy serial numbers, the Philadelphia Inquirer explains, include those in which every digit is the same or consecutive, the number is very low, or there are two sets of the same digits—for example, 77773333.
Those are just a few of the features that attract collectors. The $10 bill in question, from 1933, has the "number one" serial number A00000001A, and it also says it's "payable in silver coin to bearer on demand." Just 552,000 "silver certificate" notes were printed, and only 184,000 released, Paper Money magazine reports; soon afterward, the government recalled them, leaving just 15,000 in circulation by mid-1935. "Find one of the most beat-up ones available ... and that note will still be worth $5,000," says an expert, who values Baeder's bill at at least $500,000. Read more about how to get your hands on a "fancy serial number" bill here.