Cheapest priced copy (Duel Decks: Ajani vs. Nicol Bolas): $0.35 at Card Kingdom, near mint, their price list as of .
Briarhorn 
Creature — Elemental · 3/3 · Uncommon · Lorwyn · #199
Flash
When this creature enters, target creature gets +3/+3 until end of turn.
Evoke {1}{G} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
5 printings · $0.35 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Ajani vs. Nicol Bolas | 14 | Uncommon | $0.35 | — |
| Duel Decks: Nissa vs. Ob Nixilis | 3 | Uncommon | $0.35 | — |
| Planechase | 69 | Uncommon | $0.35 | — |
| Lorwyn | 199 | Uncommon | $0.35 | $0.79 |
| The List | DDR-3 | Uncommon | $0.35 | — |
One ruling from Wizards of the Coast
- 15 April 2013If you cast this card for its evoke cost, you may put the sacrifice trigger and the regular enters-the-battlefield trigger on the stack in either order. The one put on the stack last will resolve first.