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PCAs Jay pointed out, "common" in the hobby means non-HOFer/non-star, with a few exceptions like the Black Sox players. Hal Chase and Joe Wood are good examples of non-HOF stars ... certainly not "commons". Roger Maris is a good example for more modern players.
As such "common" has nothing to do with rarity, as there are many examples of uncommon/rare/expensive cards of "common" players.