Cheapest priced copy (Dragons of Tarkir): $0.35 at Card Kingdom, near mint, their price list as of .
Silkwrap 
Enchantment · Uncommon · Dragons of Tarkir · #38
When this enchantment enters, exile target creature with mana value 3 or less an opponent controls until this enchantment leaves the battlefield. (That creature returns under its owner's control.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dragons of Tarkir | 38 | Uncommon | $0.35 | $0.49 |
| Pioneer Challenger Decks 2021 | 4 | Uncommon | $0.35 | — |
7 rulings from Wizards of the Coast
- 25 February 2015Face-down creatures have a mana value of 0. If one is exiled by Silkwrap, it will return to the battlefield face up.
- 25 February 2015Silkwrap's ability causes a zone change with a duration, a style of ability that's somewhat reminiscent of older cards like Oblivion Ring. However, unlike Oblivion Ring, cards like Silkwrap have a single ability that creates two one-shot effects: one that exiles the creature when the ability resolves, and another that returns the exiled card to the battlefield immediately after Silkwrap leaves the battlefield.
- 25 February 2015The exiled card returns to the battlefield immediately after Silkwrap leaves the battlefield. Nothing happens between the two events, including state-based actions.
- 25 February 2015If a creature token is exiled, it ceases to exist. It won't be returned to the battlefield.
- 25 February 2015If Silkwrap leaves the battlefield before its triggered ability resolves, the target creature won't be exiled.
- 25 February 2015In a multiplayer game, if Silkwrap's owner leaves the game, the exiled card will return to the battlefield. Because the one-shot effect that returns the card isn't an ability that goes on the stack, it won't cease to exist along with the leaving player's spells and abilities on the stack.
- 25 February 2015Auras attached to the exiled creature will be put into their owners' graveyards. Equipment attached to the exiled creature will become unattached and remain on the battlefield. Any counters on the exiled creature will cease to exist.