Cheapest priced copy (Khans of Tarkir): $0.35 at Card Kingdom, near mint, their price list as of .
Barrage of Boulders 
Sorcery · Common · The List · #KTK-100
Barrage of Boulders deals 1 damage to each creature you don't control.
Ferocious — If you control a creature with power 4 or greater, creatures can't block this turn.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Khans of Tarkir | 100 | Common | $0.35 | $0.49 |
| The List | KTK-100 | Common | $0.35 | — |
3 rulings from Wizards of the Coast
- 20 September 2014Some ferocious abilities that appear on instants and sorceries use the word “instead.” These spells have an upgraded effect if you control a creature with power 4 or greater as they resolve. For these, you only get the upgraded effect, not both effects.
- 20 September 2014Barrage of Boulders deals damage only to creatures you don’t control as it resolves. However, the ferocious ability affects all creatures, including ones you control and ones that weren’t on the battlefield as Barrage of Boulders resolved.
- 20 September 2014Ferocious abilities of instants and sorceries that don’t use the word “instead” will provide an additional effect if you control a creature with power 4 or greater as they resolve.