I disagree with this - in its entirety. When someone posts a WTB for a rare book and a person has it, it doesn't mean they want to sell it or that they are a "seller." If you email them, let you know you have a copy, and tell them that they can make an offer, it gives them a lot of information. That doesn't mean you are now beholden to sell it to them for GPA or you are a "dbag." It gives them the opportunity to decide if they want to make a strong move at the book to acquire it or not. Whatever the case, they know where one is, if circumstances change, they get more information, or they decide they REALLY want it. If you have never collected truly rare comics, this may sound foreign. But I am here to tell you, that is how rare comics get moved. I think promulgating the idea that someone who identifies that they have the sought after book and they will move it for a price that motivates them, is a "dbag," is fundamentally wrong.