Cheapest priced copy (Tarkir: Dragonstorm Promos): $0.49 at Card Kingdom, near mint, their price list as of .
Fangkeeper's Familiar 
Creature — Snake · 3/3 · Rare · Tarkir: Dragonstorm Promos · #183p
Flash
When this creature enters, choose one —
• You gain 3 life and surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
• Destroy target enchantment.
• Counter target creature spell.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
4 printings · $0.49 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Tarkir: Dragonstorm Promos | 183p | Rare | $0.49 | $0.49 |
| Tarkir: Dragonstorm Promos | 183s | Rare | — | $0.79 |
| Tarkir: Dragonstorm | 183 | Rare | $0.49 | $0.49 |
| Tarkir: Dragonstorm | 357 | Rare | $0.49 | $0.79 |