Bicentennial quarters were minted in large quantities for the 200th anniversary of the United States' independence and typically hold more sentimental or historical value than monetary value.
These quarters were produced in 1975 and 1976 to commemorate America's Bicentennial. They feature a special design with the dual date "1776-1976" and are not rare in the general sense, as millions were minted.
Most Bicentennial quarters, unless they have rare errors or are in exceptionally pristine condition (such as uncirculated or proof grades), are worth only a small premium over their face value.
The value of a coin is typically influenced by its rarity, demand, condition, and historical significance. Errors or unique features can also add to a coin's value. However, for a coin to be valued at $100 million, it would have to be extraordinarily rare and significant.
If you come across claims of an exceptionally high-value Bicentennial quarter, it would be prudent to approach them with skepticism and conduct thorough research or consult with reputable numismatic experts.