Christie's Antiquities auction, scheduled for December 11th, contains an item of particular interest to those in the RPG business -- a 2nd century Roman 20-sided die.  The glass die is incised with a symbol on each face. 

This Roman die pre-dates the invention of Dungeons and Dragons in Lake Geneva, Wisconsin, by roughly 1,700 years.  It's just the thing to pick up to make your store the place with the 'first d20.' 

The expected price range is $4000 to $6000.