Mystery boxes are how sellers get rid of junk they could not move all weekend. For every person who pulls a gem there are fifty who end up with water damaged copies of Micronauts and a scratched up WildC.A.T.s foil cover. Six bucks is not a win, it is a slot machine pull, and calling it a win just feeds the next guy who sets up that box. You got lucky, plain and simple, and the odds say the next person who hands over six dollars walks away with paper they cannot even give away.