Cheapest priced copy (Outlaws of Thunder Junction): $0.99 at Card Kingdom, near mint, their price list as of .
Selvala, Eager Trailblazer 
Legendary Creature — Elf Scout · 4/5 · Mythic · Outlaws of Thunder Junction Promos · #231p
Vigilance
Whenever you cast a creature spell, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."
{T}: Choose a color. Add one mana of that color for each different power among creatures you control.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
4 printings · $0.99 to $2.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Outlaws of Thunder Junction | 231 | Mythic | $0.99 | $0.99 |
| Outlaws of Thunder Junction | 363 | Mythic | $1.49 | $2.49 |
| Outlaws of Thunder Junction Promos | 231p | Mythic | $0.99 | $1.49 |
| Outlaws of Thunder Junction Promos | 231s | Mythic | — | $1.99 |
3 rulings from Wizards of the Coast
- 12 April 2024Selvala’s last ability doesn’t care what color or colors the creatures you control are. It cares only about the power of those creatures.
- 12 April 2024Selvala’s last ability is a mana ability. It doesn’t use the stack and can’t be responded to.
- 12 April 2024Selvala’s last ability looks at the creatures you control as it resolves to determine how much mana of the chosen color to add. For example, if you control Selvala (a 4/5 creature), a 1/1 creature, and a 2/1 creature, there are three different powers among creatures you control.