Cheapest priced copy (Ultimate Masters): $1.49 at Card Kingdom, near mint, their price list as of .
Nourishing Shoal 
Instant — Arcane · Rare · Betrayers of Kamigawa · #137
You may exile a green card with mana value X from your hand rather than pay this spell's mana cost.
You gain X life.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
2 printings · $1.49 to $27.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Betrayers of Kamigawa | 137 | Rare | $2.79 | $27.99 |
| Ultimate Masters | 175 | Rare | $1.49 | $4.99 |
2 rulings from Wizards of the Coast
- 7 December 2018If a card in a player's hand has {X} in its mana cost, X is considered to be 0.
- 7 December 2018If a spell has {X} in its mana cost, include the value chosen for that X when determining the mana value of that spell, even if it was cast for an alternative cost and no mana was spent on X.