Cheapest priced copy (Secret Lair Drop): $37.99 at Card Kingdom, near mint, their price list as of .
Sliver Legion 
Legendary Creature — Sliver · 7/7 · Mythic · Time Spiral Remastered · #261
All Sliver creatures get +1/+1 for each other Sliver on the battlefield.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
6 printings · $37.99 to $199.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Future Sight | 158 | Rare | $54.99 | $199.99 |
| Judge Gift Cards 2019 | 2 | Mythic | — | $119.99 |
| Secret Lair Drop | 1149 | Mythic | $39.99 | $42.99 |
| Secret Lair Drop | 1150 | Mythic | $37.99 | $39.99 |
| Secret Lair Drop | 1310 | Mythic | — | $42.99 |
| Time Spiral Remastered | 261 | Mythic | $42.99 | $59.99 |
4 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.
- 19 March 2021If Sliver Legion and two other Slivers are on the battlefield, for example, each of them gets +2/+2.
- 19 March 2021Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a Sliver may become lethal if another Sliver leaves the battlefield during that turn.