Cheapest priced copy (Ravnica: Clue Edition): $4.99 at Card Kingdom, near mint, their price list as of .
Mastermind Plum 
Legendary Creature — Human Wizard · 2/2 · Rare · Ravnica: Clue Edition · #3
Whenever Mastermind Plum attacks, exile up to one target card from a graveyard. If an artifact card was exiled this way, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever you cast a spell, if mana from a Treasure was spent to cast it, you draw a card and you lose 1 life.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $4.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ravnica: Clue Edition | 3 | Rare | $4.99 | — |