Stores and people's homes and storage facilities are full of junk. There are television shows displaying "experts" telling the gullible and expectant owners of this crap just how much their junk is worth.

Basically, things become collectible when someone decides they can't live without it. They become rare when so many mommies have thrown out their kid's collectibles that there are few for the adult kid to moan about and wish to have another one. A rare turd is still a turd, unless it came from an extinct animal or bird. Then it becomes priceless. How much will a priceless object cost you? Depends upon how high you are willing to bid.