Cheapest priced copy (Nemesis): $0.35 at Card Kingdom, near mint, their price list as of .
Angelic Favor 
Instant · Uncommon · The List · #NEM-1
If you control a Plains, you may tap an untapped creature you control rather than pay this spell's mana cost.
Cast this spell only during combat.
Create a 4/4 white Angel creature token with flying. Exile it at the beginning of the next end step.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper