To me it depends on the denom and the clientel. Lower denoms should have higher quantites as there are more collectors.

Do you plan that these be on the tables be played and become part of the rack or sold from the cage/gift shop? Maybe get them from the table and provide a keychain holder at the cage?

2000 is nice cause hard-core collectors can get them reasonably easily (especially if you make it available via post ) and then there are plenty left for casual players who get into the hobby by seeing them on the tables. You can even design the chip with a "take me home" tag....