Cheapest priced copy (Commander Legends: Battle for Baldur's Gate): $0.35 at Card Kingdom, near mint, their price list as of .
Steadfast Unicorn 
Creature — Unicorn · 1/2 · Common · The List · #CLB-44
{3}{W}: Creatures you control get +1/+1 and gain vigilance until end of turn. Activate only during your turn. (Attacking doesn't cause them to tap.)
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Legends: Battle for Baldur's Gate | 44 | Common | $0.35 | $0.49 |
| Foundations Jumpstart | 103 | Common | $0.35 | — |
| The List | CLB-44 | Common | $0.35 | — |