The notion of a Bicentennial Quarter worth nearly $40 million and three more valued over $300,000 each is quite remarkable. Such valuations would imply extraordinary rarity or unique attributes among these coins.
Minting Errors: Quarters with significant minting errors, like double strikes or off-center strikes, can fetch high prices among collectors.
Proof Coins: Proof versions of Bicentennial Quarters, which are specially minted for collectors with polished dies and planchets, can hold higher values, especially if they're in pristine condition.
Historical Significance: Quarters with unique historical provenance or ties to significant events in American history could command premium prices.
Exceptional Condition: Coins in exceptional condition, graded as Mint State (MS) or Proof (PR) by reputable grading services, can carry higher values due to their rarity and desirability among collectors.
Limited Mintage: Varieties with extremely limited mintage figures, perhaps due to special releases or errors during production, can be highly sought after by collectors.