I know exactly how you feel. For me, it always boils down to the thought of selling the equipment and only getting peanuts for it. I always think, okay, I could sell this and have a few extra hundred dollars in my pocket, or I could keep it *in case* I ever want to use it again. I always choose the latter. There is some car audio stuff I'm sure I'll never use again...Phoenix Gold amp, Alpine head unit, MB Quart speakers, etc. When I go through the thought process above, I always choose to keep it.
I have PSB Stratus Golds which almost never get used now, but I love them so much I can't sell them. I guess once my house gets too full of junk, I may start to think twice at that point.