If a Bicentennial Quarter is in a perfect or nearly perfect condition (e.g., MS-70 or Proof-70 grade), it might be valued higher but still only in the range of a few hundred dollars at most.
The U.S. Mint also produced a limited number of Bicentennial Quarters in a 40% silver-clad format. These silver versions are more valuable than the standard clad coins but typically only reach values in the tens of dollars, not millions.
Coins with rare minting errors can be more valuable. However, even the most valuable error coins in numismatic history do not approach the $80 million mark.
In extremely rare cases, a coin with significant historical provenance could have an increased value, but this is unlikely for Bicentennial Quarters.