 Don't throw away anything that you think you might use someday. Be prepared. You might need those old screws off that thing you just took apart. Put them in a can and keep them. You never know, you might need them someday, right? And then you'll be really glad when you have them. For example, I once found a box of doorknobs at a garage sale for $2. There were at least 12 in that little cardboard box.