Cheapest priced copy (Adventures in the Forgotten Realms): $0.35 at Card Kingdom, near mint, their price list as of .
Purple Worm 
Creature — Worm · 8/7 · Uncommon · Adventures in the Forgotten Realms · #332
This spell costs {2} less to cast if a creature died this turn.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Adventures in the Forgotten Realms | 201 | Uncommon | $0.35 | $0.49 |
| Adventures in the Forgotten Realms | 332 | Uncommon | $0.35 | $0.49 |
| Adventures in the Forgotten Realms Promos | 201p | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 23 July 2021If a player casts a spell that targets multiple permanents their opponent controls with ward, each of those ward abilities will trigger. If that player doesn't pay for all of them, the spell will be countered.
- 23 July 2021Purple Worm's first ability will never reduce its cost more than {2}, no matter how many creatures died this turn.