Cheapest priced copy (Battle for Zendikar): $0.35 at Card Kingdom, near mint, their price list as of .
Altar's Reap 
Instant · Common · Battle for Zendikar · #103
As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
9 printings · $0.35 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Battle for Zendikar | 103 | Common | $0.35 | $0.79 |
| Commander 2015 | 112 | Common | $0.35 | — |
| Commander Anthology | 45 | Common | $0.35 | — |
| Conspiracy: Take the Crown | 127 | Common | $0.35 | $0.99 |
| Conspiracy | 112 | Common | $0.35 | $0.99 |
| Duel Decks: Nissa vs. Ob Nixilis | 37 | Common | $0.35 | — |
| Innistrad | 86 | Common | $0.35 | $0.49 |
| Magic 2014 | 84 | Common | $0.35 | $0.99 |
| The List | DDR-37 | Common | $0.35 | — |
2 rulings from Wizards of the Coast
- 15 April 2013You must sacrifice exactly one creature to cast this spell; you cannot cast it without sacrificing a creature, and you cannot sacrifice additional creatures.
- 15 April 2013Players can only respond once this spell has been cast and all its costs have been paid. No one can try to destroy the creature you sacrificed to prevent you from casting this spell.