Cheapest priced copy (Ixalan): $0.35 at Card Kingdom, near mint, their price list as of .
Rallying Roar 
Instant · Uncommon · Ixalan · #30
Creatures you control get +1/+1 until end of turn. Untap them.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ixalan | 30 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 29 September 2017Untapped creatures you control get +1/+1 even though Rallying Roar doesn’t untap them.
- 29 September 2017Rallying Roar affects only creatures you control at the time it resolves. Creatures you begin to control later in the turn won’t get +1/+1.