wow that is scary. That just PROVES that it is really smart to check these coins on the pcgs/ngc site. I recently pulled up one = an MS66 spanish trail- commem that said "contact NGC" I let the seller know (he was a very reputable dealer) and HE got it from another reputable dealer. turns out it was a clerical or other error and was easily resolved but it gave us both a good scare because it was an expensive coin. Now I check them all- regardless of price- and have never seen another that didn't verify but I'm sure they are out there. These people are going to get smarter and more desperate every day and will prey upon all of us because we assume its ok- after all- "its in a slab"- It takes about 30 seconds to check, and could save you untold headaches-- especially if you buy it and eventually sell it- and the new buyer checks it. Guess who will eat that one? Not the person who sold it to you---especially if its been a while.
The price as it stands now is simple. Take them to a couple places who buy bulk silver and get a price. If you want more than that- you need to do the following: Go online and printout a list of the key dates for washington quarters. sort all 1500 of them, by decade first, all the 30s, in one jar, 40s in one jar, 50s in another jar, etc, then sort by year. This way you can determine if you have any of the key dates, 1934 D and S, `1934 DDO, 1937/42D/43/50 errors I dont remember what all of them are so look online. Assuming you have some key dates, get them looked at by a knowledgable person to determine the grade- or buy the ana grading book- OR- you can use photograde on another website. Then you can sell those coins on ebay and sell the remainder by the roll for melt value.