How much is a misprinted quarter worth?

Answer 1

To clear things up, coins are STRUCK or MINTED. Printing refers to paper and ink (if the quarter was printed on paper my guess it that is is fake and you should get rid of it before the cops come)

There are many different types of mis-strikes ranging from filled dies to multiply-struck coins, blank planchets, clipped coins, and so on. Prices can range from a few cents extra to a couple of hundred dollars depending on the nature of the error. You'll need to post a new question with a specific description of the suspected error in order for one of us to evaluate it.

Answer 2

Yes, most are collectible and valued by collectors.