trashsure - Any discarded object that is of dubious value could be either a piece of total crap or that missing "thing" that will finally make your life complete. To be a true trashsure, the object must be confusing as to its function or why someone would ever own the object and then throw it away in the first place.
Half Trash and Half Treasure.
e.g., Check out this hot pink plastic stuffed rhino-head, Shelley. Can you believe that someone threw this out. It's just the trashsure I need to complete my collection of ....