Cheapest priced copy (Ice Age): $0.35 at Card Kingdom, near mint, their price list as of .
Earthlore 
Enchantment — Aura · Common · Ice Age · #231
Enchant land you control
Tap enchanted land: Target blocking creature gets +1/+2 until end of turn. Activate only if enchanted land is untapped.
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern
1 printing · $0.35 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ice Age | 231 | Common | $0.35 | — |