Cheapest priced copy (Eldritch Moon): $0.35 at Card Kingdom, near mint, their price list as of .
Galvanic Bombardment 
Instant · Common · Eldritch Moon · #129
Galvanic Bombardment deals X damage to target creature, where X is 2 plus the number of cards named Galvanic Bombardment in your graveyard.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Eldritch Moon | 129 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 13 July 2016Because Galvanic Bombardment is still on the stack as you determine the value of X, it is not in your graveyard and will not add to the value of X.