Category 3: Anything that isn't disposable or a tool. Most stuff can be of value to others once you are done using it. I treat all my stuff with care, because some day I might want to sell it, or give it away to someone. Whether it's a book, electronics, kitchenware, or furniture doesn't really matter; The value of the item (in money or in usefulness to the recipient) will always be higher the better condition something is in. You also are less likely to have to buy replacement items if you are careful with them in the first place. I agree in that you shouldn't treat everything like porcelain, but there is definitely value in treating your things with care.