Cheapest priced copy (Guildpact): $0.35 at Card Kingdom, near mint, their price list as of .
Benediction of Moons 
Sorcery · Common · Guildpact · #3
You gain 1 life for each player.
Haunt (When this spell card is put into a graveyard after resolving, exile it haunting target creature.)
When the creature this card haunts dies, you gain 1 life for each player.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
2 printings · $0.35 to $0.49 at Card Kingdom
One ruling from Wizards of the Coast
- 1 February 2006"For each player" means for each player currently in the game, which is normally two. A Two-Headed Giant game has four players. In a Free-for-All multiplayer game, players who have been eliminated or who are outside your range of influence don't count toward the total.