Cheapest priced copy (Time Spiral): $0.35 at Card Kingdom, near mint, their price list as of .
Dementia Sliver 
Creature — Sliver · 3/3 · Uncommon · Time Spiral · #236
All Slivers have "{T}: Choose a card name. Target opponent reveals a card at random from their hand. If that card has the chosen name, that player discards it. Activate only during your turn."
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.35 to $1.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Time Spiral | 236 | Uncommon | $0.35 | $1.99 |
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.