Cheapest priced copy (Kamigawa: Neon Dynasty): $0.79 at Card Kingdom, near mint, their price list as of .
Invoke Calamity 
Instant · Rare · Kamigawa: Neon Dynasty Promos · #147p
You may cast up to two instant and/or sorcery spells with total mana value 6 or less from your graveyard and/or hand without paying their mana costs. If those spells would be put into your graveyard, exile them instead. Exile Invoke Calamity.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
5 printings · $0.79 to $4.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Kamigawa: Neon Dynasty | 147 | Rare | $0.79 | $1.49 |
| Kamigawa: Neon Dynasty | 384 | Rare | $1.79 | $4.49 |
| Kamigawa: Neon Dynasty | 467 | Rare | $0.99 | $4.49 |
| Kamigawa: Neon Dynasty Promos | 147p | Rare | $0.99 | $3.49 |
| Kamigawa: Neon Dynasty Promos | 147s | Rare | — | $2.49 |
4 rulings from Wizards of the Coast
- 18 February 2022If you cast a spell without paying its mana cost, you can't choose to cast it for any alternative costs. You can, however, pay any additional costs. If the spell has any mandatory additional costs, you must pay those.
- 18 February 2022The spells are cast one after the other during the resolution of Invoke Calamity. The one you cast second will be the first one to resolve.
- 18 February 2022If the spell has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
- 18 February 2022Invoke Calamity looks for the mana values and types of the spells on the stack, not the mana values and types of the cards in your graveyard. Notably, this means that you may cast the back face of a modal double-faced card or either face of a split card as long as the spells you are casting are either instants or sorceries and together have a total mana value of 6 or less.