
Cheapest priced copy (Oath of the Gatewatch): $0.35 at Card Kingdom, near mint, their price list as of .
Grip of the Roil 

Instant · Uncommon · Oath of the Gatewatch · #56
Surge {1}{U} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Tap target creature. It doesn't untap during its controller's next untap step.
Draw a card.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Oath of the Gatewatch | 56 | Uncommon | $0.35 | $0.49 |
| The List | OGW-56 | Uncommon | $0.35 | — |
6 rulings from Wizards of the Coast
- 22 January 2016Casting a spell for its surge cost doesn't change its mana cost or its mana value.
- 22 January 2016The other spell that you or a teammate cast can be one that's resolved, one that was countered, or (for instants with surge) one that's still on the stack.
- 22 January 2016For some cards, surge represents only an alternative cost, a discount that applies if you or a teammate has cast another spell this turn. Other cards, like Reckless Bushwhacker, have additional abilities or effects if you paid the surge cost to cast the spell.
- 22 January 2016Grip of the Roil tracks the creature, but not its controller. If the creature changes controllers before its first controller's next untap step has come around, then it won't untap during its new controller's next untap step.
- 22 January 2016If an instant or sorcery spell cast for its surge cost is copied, the copy is also considered to have had its surge cost paid.
- 22 January 2016Grip of the Roil can target a creature that's already tapped. It still won't untap during its controller's next untap step.