Pull any invoice out of your pockets. See the darkish inexperienced numbers on the top-left and top-right corners? These are serial numbers, and a few are extra uncommon than others. For those who occur to have paper cash with a singular or fascinating serial quantity, it could be price rather more than face worth. In actual fact, collectors are sometimes keen to pay large bucks — tons of and even hundreds of {dollars} — for uncommon paper…
