Cheapest priced copy (Innistrad: Crimson Vow Promos): $0.49 at Card Kingdom, near mint, their price list as of .
Path of Peril 
Sorcery · Rare · Innistrad: Crimson Vow · #373
Cleave {4}{W}{B} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Destroy all creatures [with mana value 2 or less].
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
5 printings · $0.49 to $2.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Innistrad: Double Feature | 391 | Rare | $0.69 | $2.49 |
| Innistrad: Crimson Vow Promos | 124p | Rare | $0.49 | $0.49 |
| Innistrad: Crimson Vow Promos | 124s | Rare | — | $0.79Out of stock |
| Innistrad: Crimson Vow | 124 | Rare | $0.49 | $0.49 |
| Innistrad: Crimson Vow | 373 | Rare | $0.49 | $0.49 |
4 rulings from Wizards of the Coast
- 19 November 2021A cleave cost is an alternative cost that's paid instead of the spell's mana cost. Casting a spell for its cleave cost doesn't change the spell's mana value.
- 19 November 2021If you cast a spell for its cleave cost, that spell doesn't have any of the text in square brackets while it's on the stack.
- 19 November 2021You can't cast a spell for both its cleave cost and another alternative cost. For example, if an effect gives an Alchemist's Retrieval in your graveyard a flashback cost of {U}, you can't cast it from your graveyard for its cleave cost.
- 19 November 2021If an effect allows you to “cast a spell without paying its mana cost,” you can't cast that spell for its cleave cost.