Secured inside your lock box or tucked away in a dresser drawer, your $2 bill might be worth far more than its face value.

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.

Everyone is familiar with dollars, fives, 10s and 20s, but $2 bills are still out there, and they could be worth a lot of money. An auction site called U.S. Currency Auctions estimates that ...