Unless there are circumstances like an impending move, or I am running out of space in the closet.
It's kind of a difficult line to walk. I used to keep way too much stuff. But just yesterday I pulled equipment (tools, a VGA cable, a prototyping board) out of the back of my closet that I hadn't used in four or five years, and was able to save myself a couple hundred bucks (computer repair). That VGA cable occupies very little space.