Cheapest priced copy (Innistrad: Crimson Vow): $0.35 at Card Kingdom, near mint, their price list as of .
Markov Purifier 
Creature — Vampire Cleric · 2/3 · Uncommon · Innistrad: Crimson Vow · #312
Lifelink
At the beginning of your end step, if you gained life this turn, you may pay {2}. If you do, draw a card.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $0.35 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Innistrad: Double Feature | 508 | Uncommon | $0.59 | $1.49 |
| Innistrad: Crimson Vow | 241 | Uncommon | $0.35 | $0.49 |
| Innistrad: Crimson Vow | 312 | Uncommon | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 19 November 2021Markov Purifier's ability triggers if you gained any amount of life that turn, even if you also lost that much or more life.