Cheapest priced copy (Ice Age): $7.99 at Card Kingdom, near mint, their price list as of .
Altar of Bone 
Sorcery · Rare · Ice Age · #281
As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card, reveal it, put it into your hand, then shuffle.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $7.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ice Age | 281 | Rare | $7.99 | — |
3 rulings from Wizards of the Coast
- 4 October 2004Because the “search” requires you to find a card with certain characteristics, you don’t have to find the card if you don’t want to.
- 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.