Here's a thought, to help you balance the "just because" reasoning with the reality of keeping something you don't think you really want or will use. (This is coming from someone who bought a 15-91 two years ago and had everything fixed on it but the timing is still off, so I've never used it.) Mine is in a cabinet which takes up a lot of room, especially since the machine is useless as is.
I would say give yourself a statute of limitations with it. Maybe a year. See if it "grows on you"--either in a good way, or like a fungus! haha. I used to be a keeper of everything because of sentiment, but realize that it's a burden once the sentiment has worn off. Instead of keeping the thing itself, keep a picture of it. I'm sure you could find a buyer in a year's time. A yard sale isn't necessarily the best venue.