Cheapest priced copy (Amonkhet): $0.35 at Card Kingdom, near mint, their price list as of .
Cartouche of Ambition 
Enchantment — Aura Cartouche · Common · Amonkhet · #83
Enchant creature you control
When this Aura enters, you may put a -1/-1 counter on target creature.
Enchanted creature gets +1/+1 and has lifelink.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
2 printings · $0.35 to $0.79 at Card Kingdom
4 rulings from Wizards of the Coast
- 18 April 2017Cartouche is an enchantment subtype with no special meaning. Other cards may care about which enchantments are Cartouches.
- 18 April 2017The target creature for the triggered ability of Cartouche of Ambition doesn't have to be the creature it enchants.
- 18 April 2017Each Cartouche is an Aura with "Enchant creature you control." If another player gains control of either the Cartouche or the enchanted creature (but not both), then the Cartouche will be enchanting an illegal permanent and be put into its owner's graveyard as a state-based action.
- 18 April 2017If the target creature becomes an illegal target before a Cartouche spell resolves, the spell doesn't resolve. It doesn't enter the battlefield.