The vendor is anyone, the same as anyone else (albeit some are dishonest), and they have found or bought or created these coins and they are aiming to sale them to generate money. I take advantage of the standard or collector grading described in Amassing Confederate Paper Money along with https://cesarijkjh.bcbloggers.com/33574265/5-easy-facts-about-how-to-tell-a-dollar-is-fake-described