Cheapest priced copy (Planar Chaos): $0.35 at Card Kingdom, near mint, their price list as of .
Poultice Sliver 
Creature — Sliver · 2/2 · Common · Planar Chaos · #11
All Slivers have "{2}, {T}: Regenerate target Sliver." (The next time that Sliver would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
2 printings · $0.35 to $2.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Planar Chaos | 11 | Common | $0.35 | $1.99 |
| Time Spiral Remastered | 33 | Uncommon | $0.35 | $2.49Out of stock |
2 rulings from Wizards of the Coast
- 1 July 2013If the creature type of a Sliver changes so it's no longer a Sliver, it will no longer be affected by its own ability. Its ability will continue to affect other Sliver creatures.
- 1 July 2013Abilities that Slivers grant, as well as power/toughness boosts, are cumulative. However, for some abilities, like flying, having more than one instance of the ability doesn't provide any additional benefit.