You could contact Custom Dice about an actual printed die:http://www.customdice.com/game_designs.php
Or Q-Workshop for a custom engraved die:
But they ain't cheap: the engraved has a quote of 20 dice for $140, only getting down to the $2-3 range for runs of 1000. I'm pretty sure Custom Dice is cheaper (around $3 a die for short runs).
Definitely a small press or group buy proposition.