Cheapest priced copy (Oath of the Gatewatch): $0.35 at Card Kingdom, near mint, their price list as of .
Sky Scourer 
Creature — Eldrazi Drone · 1/2 · Common · Oath of the Gatewatch · #78
Devoid (This card has no color.)
Flying
Whenever you cast a colorless spell, this creature gets +1/+0 until end of turn.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Oath of the Gatewatch | 78 | Common | $0.35 | $0.49 |