I wouldn't be often that the number of examples of a chip that JamesC knows of would decrease and increase the Rarity (scale of 1 to 10).

There are cases where new finds or hoards of a previously scarce chip make more available and would decrease the Rarity. My guess is this occurs for a fraction of a percent of the thousands of different collectible chips that James catalogs.

In general, the Rarity number is useful but a buyer must be aware that for a few chips, Rarity may decrease. Part of the collecting game is keeping up with new finds, digs, and hoards of chips.

Thanks for a great pictorial chip reference James!