What are pre 1965 US solid silver quarter dollars worth?

Answer 1

They're not pure silver, they're 90% silver.

If you have common-date 90% silver coins in circulated condition, the price will fluctuate with the precious metals market. Currently, the spot price of silver is somewhere near $14 a troy ounce. At that price, the melt value of a quarter is $2.50, so a dealer should pay about $2 for a pre-65 quarter and sell one for $3. In large quantities ($1000 bags) the prices will be closer to the melt value.

Answer 2

The value is for the silver at $2.25 as of today.