Cheapest priced copy (Magic Origins): $2.99 at Card Kingdom, near mint, their price list as of .
Willbreaker 
Creature — Human Wizard · 2/3 · Rare · Magic Origins · #84
Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control this creature.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $2.99 to $9.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic Origins | 84 | Rare | $2.99 | $6.99 |
| Magic Origins Promos | 84s | Rare | — | $9.49 |
3 rulings from Wizards of the Coast
- 22 June 2015If you lose control of Willbreaker before its ability resolves, you won’t gain control of the creature at all.
- 22 June 2015If Willbreaker leaves the battlefield, you no longer control it, and its control-change effect ends.
- 22 June 2015If another player gains control of Willbreaker, its control-change effect ends. Regaining control of Willbreaker won’t cause you to regain control of the creature.