An auction site called U.S. Currency Auctions estimates that uncirculated $2 bills from 1890 could sell for at least $4,500.

Its secured inside your lock box or deep in a dresser drawer - the $2 bill. But some of the less-used currency could be worth ...

If you have a $2 bill burning a hole in your pocket, think twice before spending it at some store. The bill itself might be worth a lot more than two dollars — enough to build some serious wealth.