Cheapest priced copy (Magic 2011): $0.35 at Card Kingdom, near mint, their price list as of .
Volcanic Strength 
Enchantment — Aura · Common · Magic 2011 · #158
Enchant creature
Enchanted creature gets +2/+2 and has mountainwalk. (It can't be blocked as long as defending player controls a Mountain.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic 2011 | 158 | Common | $0.35 | $0.49 |
| Magic 2013 | 155 | Common | $0.35 | $0.49 |