On a slightly newer time scale there are always firearm collectors searching for something impossible to acquire now, but which might have been acquired at some point in the past and squirreled away in its factory original box in the cosmoline. Like somebody who might have purchased an imported Egyptian Maadi AKM (locally made AK47 variant) in 1982, then never unpacked it for whatever reason.
People collect these things just because, almost like pokemon cards, another example would be the rarity of finding a specific year of East German Makarov in pristine/factory new condition.
15 years or so ago when I was more into guns I spent a _lot_ of time on historical firearm sites looking for Martini-Henry rifles. There were still a trickle of them turning up straight from caches in Afghanistan (maybe other countries too). I never bought any because I was just a teenager, and now prices have more than doubled, of course.
And these things do exist - I know, because I have some (nascent, perhaps) - new in box LEGO sets wrapped and deep in a storage unit, spare parts still in box in the garage, etc.
Several years ago, I bought a new in box 1981 road bike. Story from the seller was an old chicago bike shop went out of business and there were some old bikes and parts in the back. The frame is big, I'm 6 foot and I barely fit. Probably they sold the bikes with regular size frames and put this in the back, and then styles changed and they forgot about it. The brake pads wore out super quick, but everything else worked fine. I went through the tubes too, but that happens. No big collectors, so the price was reasonable as a bike to use... more than a similar used bike, but much less than a similarly nice new bike.