Am I missing something?

Got a friend who geeks out over stuff like this.
He's went so far as to actively pay the girls at the to be on the lookout for anything they might feel he'd be interested in.
Of course the girls are happy to do it because he pays them well.
When we had lunch last, he was bragging to me about his latest score, $75 of sequential $1 silver certificates.
He said he bought them from some dumb girl who didn't know better and probably a junkie.
When I pointed out that those were probably stolen from another collector and now she knows where he lives, it'll be his house that gets hit next.