Cheapest priced copy (Commander 2021): $0.59 at Card Kingdom, near mint, their price list as of .
Elementalist's Palette 
Artifact · Rare · Commander 2021 · #403
Whenever you cast a spell with {X} in its mana cost, put two charge counters on this artifact.
{T}: Add one mana of any color.
{T}: Add {C} for each charge counter on this artifact. Spend this mana only on costs that contain {X}.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
3 printings · $0.59 to $2.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2021 | 76 | Rare | $0.59 | — |
| Commander 2021 | 403 | Rare | $2.49 | — |
| Secrets of Strixhaven Commander | 346 | Rare | $0.59 | — |
3 rulings from Wizards of the Coast
- 16 April 2021If you cast a spell with multiple {X} mana symbols in its cost, the first ability triggers only once.
- 16 April 2021The mana added by the last ability can be used only to pay costs with at least one {X}, but it can be used to pay for any part of that cost, not just the {X}. That {X} could be in a spell's total cost, an ability's activation cost, or a cost you're asked to pay as a spell or ability resolves.
- 16 April 2021The mana added by the last ability doesn't all have to spent on the same cost.