All were fine, but they paid me less for the bills that were old, stained, or had writing on them
For real? Where i come from, it doesn't matter if the bills are old, stained or had writing on them. As long as they aren't fake, the value remains the same.
Good to read your story, I'm guessing he never really figured out why you stopped doing business with him.
I am guessing he knows exactly why. Someone had to put all that tape around the edges to make it feel like other dollars.