I definitely see your point. I think the reason the vinyl is a bit inflated is because you get your name in the credits. Granted that doesn't justify the $20 boost, but I don't really mind since this is one of my favorite bands, but I get what you're saying.
5/18 Tyler, The Creator/Earl Sweatshirt
6/30 Mayhem Fest 2013
8/26 Black Sabbath