Cheapest priced copy (Avacyn Restored): $0.35 at Card Kingdom, near mint, their price list as of .
Demonic Taskmaster 
Creature — Demon · 4/3 · Uncommon · Avacyn Restored · #95
Flying
At the beginning of your upkeep, sacrifice a creature other than this creature.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.35 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Avacyn Restored | 95 | Uncommon | $0.35 | $0.49 |
| Innistrad Remastered | 104 | Uncommon | $0.35 | $0.49 |
| Innistrad Remastered | 377 | Uncommon | $0.35 | $0.99 |
2 rulings from Wizards of the Coast
- 1 May 2012If you control no other creatures, you won’t sacrifice anything.
- 1 May 2012If Demonic Taskmaster leaves the battlefield after its ability triggers but before it resolves, you’ll still have to sacrifice a creature. Notably, if you control two Demonic Taskmasters and no other creatures, each one will force you to sacrifice the other.