Hi Lizzie
That will be a non good idear to open your cope of the item
I had many unopened or never used items in my collection, sometimes if it is a not valued item i buy i normally get 2 one to keep excact new and one to use.
I had also been to an auction to get point of some of my items, and when its fresh it can keep up to more than the 4th time prize than an open... That became of how valued or many Peaces there are made of it single item...
And that's not only for MJ items, that can go for most other stuff that goes for an collector (Toys, Pens, Cartoons aso)
Hope my Little description help you, or you ask Again
All Best Klaus