Cheapest priced copy (Dominaria Remastered): $0.79 at Card Kingdom, near mint, their price list as of .
Damping Sphere 
Artifact · Uncommon · Dominaria Remastered · #377
If a land is tapped for two or more mana, it produces {C} instead of any other type and amount.
Each spell a player casts costs {1} more to cast for each other spell that player has cast this turn.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $0.79 to $19.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dominaria Remastered | 219 | Uncommon | $0.79 | $2.99 |
| Dominaria Remastered | 377 | Uncommon | $2.79 | $19.99 |
| Dominaria | 213 | Uncommon | $0.79 | $6.99 |
3 rulings from Wizards of the Coast
- 8 December 2022Damping Sphere’s second ability counts spells that were cast during a turn even if Damping Sphere wasn’t on the battlefield as they were cast. For example, if Damping Sphere itself is the third spell you cast in a turn, the next spell you cast costs {3} more to cast.
- 8 December 2022To determine the total cost of a spell, start with the mana cost or alternative cost (such as a flashback cost) you’re paying, add any cost increases, then apply any cost reductions. The mana value of the spell is determined only by its mana cost, no matter what the total cost to cast the spell was.
- 8 December 2022If multiple replacement effects would modify the mana an ability you control produces, choose one to apply. After that, determine if any others are applicable. A replacement effect can’t apply to the same event more than once.