IMHO there are fundamental differences between that and something that was purchased to satisfy the needs of yourself or your close associates.

There's also a world of difference between a new paperback copy of The Fellowship of the Ring for $10, and a movie from some old company that went out of business in the '70s and whichever company bought up all the scraps never bothered to capitalize on the IP, and the movie can't be purchased (new) for any price anywhere. If it's been ten years since your media was commercially available, it should be at least temporarily public domain. If you want to assert that copyright, start selling it, then you can have exclusive access to selling it again.

It's dumb how much of 20th century history has been lost because of the march of ever dumber copyright laws.