I actually need this cable, so i'll be opening it. It feels like a bit of a shame, but I'll preserve the box of course. The sheer glut of new stuff from Computer Reset basically tanked the value of any of this stuff. Any PCjr collector who wants one can have one.
Once you've opened shrinkwrap, it's best to just remove the whole thing, as the uneven stress as the shinkwrap continues to tighten can crush the box over time - although if an item is exquisitely rare and you have a mind to resell it, you may decide to let that be the next owner's problem.