Cheapest priced copy (March of the Machine Promos): $4.49 at Card Kingdom, near mint, their price list as of .
Chandra, Hope's Beacon 
Legendary Planeswalker — Chandra · Mythic · March of the Machine · #321
Whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy. This ability triggers only once each turn.
+2: Add two mana in any combination of colors.
+1: Exile the top five cards of your library. Until the end of your next turn, you may cast an instant or sorcery spell from among those exiled cards.
−X: Chandra deals X damage to each of up to two targets.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $4.49 to $5.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| March of the Machine | 134 | Mythic | $4.99 | $4.99 |
| March of the Machine | 321 | Mythic | $5.49 | $5.99 |
| March of the Machine Promos | 134p | Mythic | $4.49 | $5.99 |
| March of the Machine Promos | 134s | Mythic | — | $5.99 |
8 rulings from Wizards of the Coast
- 14 April 2023If the spell has damage divided as it was cast, the division can't be changed (although the targets receiving that damage still can). The same is true of spells that distribute counters.
- 14 April 2023If the spell that's copied is modal (that is, it includes a choice from a bulleted list of effects), the copy will have the same mode. A different mode can't be chosen.
- 14 April 2023A copy of a spell is created on the stack, so it's not "cast." Abilities that trigger when a player casts a spell won't trigger.
- 14 April 2023For the second loyalty ability, the spell you cast must be an instant or sorcery spell, although the exiled card doesn't necessarily have to be. For example, if you exile a creature card that has an Adventure, you can cast that Adventure spell.
- 14 April 2023You can't choose to pay any alternative or additional costs for the copy. However, effects based on any alternative or additional costs that were paid for the original spell are copied as though those same costs were paid for the copy.
- 14 April 2023The copy will have the same targets as the spell it's copying unless you choose new ones. You may change any number of the targets, including all of them or none of them. If, for one of the targets, you can't choose a new legal target, then it remains unchanged (even if the current target is illegal).
- 14 April 2023If the spell that's copied has an X whose value was determined as it was cast, the copy will have the same value of X.
- 14 April 2023If you copy a spell, you control the copy. It will resolve before the original spell does.