Cheapest priced copy (Tarkir: Dragonstorm Commander): $1.29 at Card Kingdom, near mint, their price list as of .
Broodcaller Scourge 
Creature — Dragon · 5/7 · Rare · Tarkir: Dragonstorm Commander · #44
Flying
Whenever one or more Dragons you control deal combat damage to a player, you may put a permanent card with mana value less than or equal to that damage from your hand onto the battlefield.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $1.29 to $2.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Tarkir: Dragonstorm Commander | 44 | Rare | $1.29 | — |
| Tarkir: Dragonstorm Commander | 84 | Rare | $2.79 | — |
One ruling from Wizards of the Coast
- 4 April 2025If a card in your hand has {X} in its mana cost, X is 0 for the purpose of determining its mana value.