Cheapest priced copy (Dominaria United): $0.35 at Card Kingdom, near mint, their price list as of .
Artillery Blast 
Instant · Common · Dominaria United · #6
Domain — Artillery Blast deals X damage to target tapped creature, where X is 1 plus the number of basic land types among lands you control.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dominaria United | 6 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 9 September 2022Domain abilities count the number of basic land types among lands you control, not how many lands you control or how many of any type.
- 9 September 2022The basic land types are Plains, Island, Swamp, Mountain, and Forest. Land types other than basic land types (such as Desert) don’t contribute to domain abilities.