Cheapest priced copy (Shards of Alara): $0.35 at Card Kingdom, near mint, their price list as of .
Tortoise Formation 
Instant · Common · Shards of Alara · #61
Creatures you control gain shroud until end of turn. (They can't be the targets of spells or abilities.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Shards of Alara | 61 | Common | $0.35 | $0.49 |