JUST IN: Mark McGwire & Chris Berman have a dual autograph card for the first time ever. The card commemorates McGwire's legendary 1999 HR Derby performance AND Berman's famous "Back, back ...

However, this is unique because it's a Triple Autograph 1/1 Superfractor signed by Mark McGwire, Rickey Henderson, and Reggie Jackson. This only helps raise it's value.