Cheapest priced copy (Dominaria United): $0.35 at Card Kingdom, near mint, their price list as of .
Jodah's Codex 
Artifact — Book · Uncommon · Dominaria United · #233
Domain — {5}, {T}: Draw a card. This ability costs {1} less to activate for each basic land type among lands you control.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dominaria United | 233 | Uncommon | $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.