These cards have always been given out to volunteers at prerelease events
9 Marshmallon You can't fill your deck with just strong monsters, you need lower starred ones to use as "tributes" and "materials" for the different types of summoning
It prevents the next single point of damage dealt to target player or creature that turn, but it also then returns to its owners hand at the end step
Like most Magic: The Gathering cards, the value of Missy depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Doctor Who)
That temptation would drive lots for ill profit practices, and as years go by and sealed product becomes less and less available, all signs point towards weighing as seller to protect buyers from the potential damage that someone else could have caused through the same practice