Cheapest priced copy (Dragons of Tarkir): $0.35 at Card Kingdom, near mint, their price list as of .
Surge of Righteousness 
Instant · Uncommon · Dragons of Tarkir · #42
Destroy target black or red creature that's attacking or blocking. You gain 2 life.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dragons of Tarkir | 42 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 25 February 2015If Surge of Righteousness resolves but the creature isn’t destroyed (perhaps because it regenerated or it has indestructible), you’ll still gain 2 life.
- 25 February 2015However, if the creature becomes an illegal target before Surge of Righteousness resolves, it won’t resolve and none of its effects will happen. You won’t gain life.