Cheapest priced copy (The Brothers' War): $0.35 at Card Kingdom, near mint, their price list as of .
Power Plant Worker 
Artifact Creature — Assembly-Worker · 4/4 · Common · The Brothers' War · #241
{3}: This creature gets +2/+2 until end of turn. If you control creatures named Mine Worker and Tower Worker, put two +1/+1 counters on this creature instead. Activate only once each turn.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| The Brothers' War | 241 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 14 October 2022Power Plant Worker will get two +1/+1 counters instead of getting +2/+2 if, at the time the ability resolves, you control at least one creature named Mine Worker and at least one creature named Tower Worker.