@The NYC Toy fair 2008 I think I saw the most dice in one place possible, Koplow has over 1,200 types of standard and polyhedral dice. They have an educational line with math, fraction, decimal, +/-, blank numbered and more. Novelty dice, mini dice, wood dice, dice bones, dice made from wood. Alphabet dice, cat dice, lobster dice. Foam dice, round dice, 30 sided dice.
When I talked to the founder, he handed me tiny dice about the size of a couple grains of rice. These folks have dice.