What are these 1976 40% silver coins worth?
 

A friend of mine inherited a set of coins and I have been trying to figure out what they are worth.

These are 1976 (bicentennial) coins. It is a set of one $0.25, one $0.50, and one $1.00 coins in a sealed wrapper, uncirculated. According to an insert, these are uncirculated 40% silver coins from the US Mint.

I had no idea that 40% silver was made in 1976. Are all bicentennial quarters (drummer on the back instead of an eagle) made of 40% silver? Also, I had no idea they had a $1 coin in 1976. It is not a Susan B Anthony coin.

Anyone know if these things are worth anything more than their silver content?