All non vintage decks literally lose all of their value once the cellophane is taken off. There are a few exceptions like the Smoke and Mirror V1's but even then, they are now worth much less than they would be if they remained unopened. My advise to you is to collect the way you want to collect. Unless you manage to get your hands on a lot of decks that that happen to be extremely valuable, like Jerry's, or invest mountains of cash into cards, you most likely will not make much money selling your collection. Just collect for you and if you like using decks, then use them; if you like having them sealed, then do that, its a personal preference.....so don't worry too much about value.