That precisely is the point. I don't remember exactly but a half-eaten cake by somebody or other went for some millions under the hammer. I mean what does it matter you have it in possession or not? I am not arguing against collection but the price you pay for it.
Actually, what make something collectable and worth money is items that were mass produced, that are now hard to find, but are still in demand. For example, a certain type of toy that was put into cereal boxes, for the kids pulled them out, played with them to destruction, but are in demand because they were the year the little car first came out, like the 57 chevy as an example for lack of another.