Cheapest priced copy (Commander Masters): $8.49 at Card Kingdom, near mint, their price list as of .
Syphon Sliver 
Creature — Sliver · 2/2 · Rare · Magic 2014 · #117
Sliver creatures you control have lifelink. (Damage dealt by a Sliver creature you control also causes you to gain that much life.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $8.49 to $13.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Masters | 870 | Rare | $8.49 | — |
| Magic 2014 | 117 | Rare | $8.49 | $13.99 |
| Secret Lair Drop | 634 | Rare | — | $11.99 |
2 rulings from Wizards of the Coast
- 1 July 2013If you change the creature type of a Sliver you control 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 you control.
- 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.