Dumb question. How do you assure yourself that the sealed monster box of silver coins is not a box of rocks. Does a monster box loose value if you open it?
Never bought a monster box, so I would not know. I'm not a big buyer, but when I do I prefer Dos Equix, seriously though: If you buy from a reputable dealer and it's US mint coins, they usually arrive in 20 coin plastic boxes, they would not lose value unless they get physically damaged, that's all I know.