Cheapest priced copy (Betrayers of Kamigawa): $0.35 at Card Kingdom, near mint, their price list as of .
Genju of the Fields 
Enchantment — Aura · Uncommon · Betrayers of Kamigawa · #5
Enchant Plains
{2}: Until end of turn, enchanted Plains becomes a 2/5 white Spirit creature with "Whenever this creature deals damage, its controller gains that much life." It's still a land.
When enchanted Plains is put into a graveyard, you may return this card from your graveyard to your hand.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.35 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Betrayers of Kamigawa | 5 | Uncommon | $0.35 | $1.49 |
| The List | BOK-5 | Uncommon | $0.35 | — |
| Salvat 2005 | G28 | Uncommon | — | — |
3 rulings from Wizards of the Coast
- 1 August 2005When activated multiple times, it will have the triggered ability multiple times. When the animated Plains deals damage, the ability will trigger once for each copy of the ability. If, for example, you activate the ability three times, the Plains will deal two damage, and you'll gain six life.
- 1 August 2008A noncreature permanent that turns into a creature can attack, and its {T} abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn't matter how long the permanent has been a creature.
- 1 October 2009Activating the ability that turns it into a creature while it's already a creature will override any effects that set its power and/or toughness to a specific number. However, any effect that raises or lowers power and/or toughness (such as the effect created by Giant Growth, Glorious Anthem, or a +1/+1 counter) will continue to apply.