If you are buying "cull" categorized coins then you can expect spot price for the silver in them. If you think they are otherwise then you need to learn about grading a bit more.
Washington Quarters before 1965 are 90% Silver.. Unless you find a transitional Mint Error (Silver planchets struck in 1965 from left over 1964 Blanks) Silver melt value + 25C each
Agree on $3 each melt. Although the 1934 could go for $4 if you are not selling to a silver/gold buyer. But you'd have to find a collector, and despite the age it's still a relatively common date. For most years Philly produced the most amount of coins and their coins are usually not as desirable. In 1934 they produced almost 32 million quarters while Denver only made 3.5 million.