[mrmopar]

I would bet there will always be a slight (to larger) premium on unopened items to some collectors, as long as the product inside keeps well. In addition to the Cereal (I don't have any full though), I do have a couple of those 80s Kraft Mac and Cheese boxes with the cut out cards & noodles still inside.

I also have a Pepsi can unopened from Michael Jackson's Dangerous Tour. The special kicker is the can was from Japan too.

One final thought. When Miller did the LA Dodgers cans and bottles with Dodgers on them in the 2000s, I tried to find someone in the LA area who could get me one each sealed. I failed, and settled for opened bottle and can. The funny thing is, those are damn near impossible to find, even empty. Weirdest thing...