Cheapest priced copy (The Lost Caverns of Ixalan): $0.35 at Card Kingdom, near mint, their price list as of .
Oaken Siren 
Artifact Creature — Siren Pirate · 1/2 · Common · The Lost Caverns of Ixalan · #66
Flying, vigilance
{T}: Add {U}. Spend this mana only to cast an artifact spell or activate an ability of an artifact source.
Legal inCommanderBrawlStandardPioneerModernLegacyVintagePauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| The Lost Caverns of Ixalan | 66 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 10 November 2023An "artifact source" is any object with the card type artifact. This means you could spend the mana to activate an ability of an artifact you control or an artifact card in your hand or graveyard, for example.