Probably 50% of the items that are on this shelf are used pens. Some are empty, others probably on the way toward being so. If there are some which are actually still good, I'm not sure it's work the effort to check them out. I lose pens with a distressing frequency, but on the other hand, I also accumulate them very rapidly. I pick them up at conferences and use them until I lose them, or put them on the shelf. If they do get to the shelf, chances are good that they're going to enjoy a lengthy stay there.