Ah, methheads, those lovable scamps. I was helping a friend sell some stuff at the swap meet when a pair of people who fit the profile arrived. They set up a couch, a lamp and an end table for sale. The woman just left and the guy went to sleep on the couch, until he just left as well. I wouldn't spend too many brain cells looking for rational behavior.
Of course, I also had a bunch of Magic Cards stolen out of my desk at work, as there was a thief who was doing a mini-crime spree on different office suites around town. I was buying them on my break as a substitute for a late afternoon snack, but because I wasn't playing at that time, the opened packs just lived in my desk. That thief was actually caught by the police with a bunch of his stolen goods later on, but alas, no Magic Cards, or so the police claimed. Of course, if somewhere, some policeman's kid is playing a Blightsteel Collossus . . .