Yeah, he's a bit of a character, but he also knows his sh!t and is a really good resource. And on top of it, what he's selling is really good. These days especially, you just don't see records in the condition that he has, that aren't on a shelf with a crazy price tag.
I an original You Are What You Is (Frank Zappa) last weekend there that looked like it had just been opened, for $20.
Here's an article from the early 2000s: