Cheapest priced copy (Zendikar Rising Promos): $0.49 at Card Kingdom, near mint, their price list as of .
Zagras, Thief of Heartbeats 
Legendary Creature — Vampire Rogue · 4/4 · Rare · Zendikar Rising · #241
This spell costs {1} less to cast for each creature in your party.
Flying, deathtouch, haste
Other creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a planeswalker, destroy that planeswalker.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $0.49 to $1.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Zendikar Rising Promos | 241p | Rare | $0.49 | $0.79 |
| Zendikar Rising Promos | 241s | Rare | — | $1.79Out of stock |
| Zendikar Rising | 241 | Rare | $0.49 | $0.79 |
| Zendikar Rising | 372 | Rare | $1.29 | $0.99 |
5 rulings from Wizards of the Coast
- 25 September 2020If a spell has a cost reduction based on the number of creatures in your party, no player may attempt to change that number after you begin to cast the spell but before you pay the cost.
- 25 September 2020If a creature has more than one party creature type, and there are multiple ways to count that creature that could result in a different number of creatures in your party, the highest such number is used. For example, if you control a Cleric and a Cleric Wizard, the number of creatures in your party is two. You can't choose to have it be just one by counting the Cleric Wizard first as a Cleric.
- 25 September 2020An ability referring to the number of creatures in your party gets a number from zero to four. Such abilities never ask which creatures are in your party, and you never have to designate specific creatures as being in your party. You can't choose to exclude creatures from this count to lower the number.
- 25 September 2020Several cards have a cost reduction based on the number of creatures in your party. To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions. The mana value of the spell is determined only by its mana cost, no matter what the total cost to cast the spell was.
- 25 September 2020To determine "the number of creatures in your party," check whether you control a Cleric, whether you control a Rogue, whether you control a Warrior, and whether you control a Wizard. The number is the total number of those checks to which you answered yes. Each creature you control can be counted for only one of those checks.