Cheapest priced copy (Innistrad: Double Feature): $0.35 at Card Kingdom, near mint, their price list as of .
Parasitic Grasp 
Instant · Uncommon · Innistrad: Crimson Vow · #123
Cleave {1}{B}{B} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Parasitic Grasp deals 3 damage to target [Human] creature. You gain 3 life.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Innistrad: Double Feature | 390 | Uncommon | $0.35 | $0.49 |
| Innistrad: Crimson Vow | 123 | Uncommon | $0.35 | $0.49 |
4 rulings from Wizards of the Coast
- 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 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 2021If an effect allows you to “cast a spell without paying its mana cost,” you can't cast that spell for its cleave cost.
- 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.