Dustin is a numismatist. When I met him he was just collecting wheat pennies, but has since expanded to include buffalo nickels, state quarters, and mercury dimes. We also collect silver certificates and older $2 bills.
I recently read an article about how all money contains trace amounts of drugs and fecal material. With that being said, what are we really collecting? Hmm..
Maybe one day we'll make some real money off the money collection.