Cheapest priced copy (Tarkir: Dragonstorm): $0.35 at Card Kingdom, near mint, their price list as of .
Lightfoot Technique 
Instant · Common · Tarkir: Dragonstorm · #14
Put a +1/+1 counter on target creature. It gains flying and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)
Legal inCommanderBrawlStandardPioneerModernLegacyVintagePauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Tarkir: Dragonstorm | 14 | Common | $0.35 | $0.49 |