Cheapest priced copy (Duel Decks: Knights vs. Dragons): $0.35 at Card Kingdom, near mint, their price list as of .
Ghostfire 
Instant · Common · Duel Decks: Merfolk vs. Goblins · #40
Ghostfire is colorless.
Ghostfire deals 3 damage to any target.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Knights vs. Dragons | 69 | Common | $0.35 | — |
| Duel Decks: Merfolk vs. Goblins | 40 | Common | $0.35 | — |
| Future Sight | 115 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 1 May 2007Ghostfire is colorless in all zones. Its damage comes from a colorless source.