Cheapest priced copy (Streets of New Capenna Promos): $0.49 at Card Kingdom, near mint, their price list as of .
Aven Heartstabber 
Creature — Bird Assassin · 1/1 · Rare · Streets of New Capenna · #433
Flying
As long as there are five or more mana values among cards in your graveyard, this creature gets +2/+2 and has deathtouch.
When this creature dies, mill two cards, then draw a card.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $0.49 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Streets of New Capenna Promos | 166p | Rare | $0.49 | $1.49 |
| Streets of New Capenna Promos | 166s | Rare | — | $0.99 |
| Streets of New Capenna | 166 | Rare | $0.49 | $0.49 |
| Streets of New Capenna | 433 | Rare | $0.49 | $0.49 |
6 rulings from Wizards of the Coast
- 29 April 2022The mana value of a split card in the graveyard is the total mana value of both halves of that card. It does not have two mana values.
- 29 April 2022X is 0 when determining the mana value of a card in your graveyard.
- 29 April 2022The mana value of a land card is 0.
- 29 April 2022The mana value of a double-faced card in your graveyard is always the mana value of the front face.
- 29 April 2022If you have five or more mana values among cards in your graveyard and then some of them are removed such that you have fewer than five mana values among those cards, Aven Heartstabber loses its bonus to power and toughness. Notably, this may cause it to die if it now has damage marked on it greater than its toughness.
- 29 April 2022“Five or more mana values among cards in your graveyard” means there are at least five different mana values among those cards.