Cheapest priced copy (Throne of Eldraine): $0.35 at Card Kingdom, near mint, their price list as of .
Clockwork Servant 
Artifact Creature — Gnome · 2/3 · Uncommon · Throne of Eldraine · #216
Adamant — When this creature enters, if at least three mana of the same color was spent to cast it, draw a card.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Throne of Eldraine | 216 | Uncommon | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 4 October 2019Adamant effects check what mana was actually spent to cast a spell. If an effect allows you to spend mana “as though it were mana” of any color or type, that allows you to spend mana you couldn't otherwise spend, but it doesn't change what mana you spent to cast the spell.
- 4 October 2019If you copy a spell that has an adamant ability, no mana was spent to cast the copy at all, so that ability won't apply.
- 4 October 2019If an effect allows you to cast a spell without paying its mana cost, you can't choose to cast it and pay unless another rule or effect allows you to cast that spell for a cost. Similarly, you can't waive a cost reduction unless that effect says you may.