Cheapest priced copy (Mirrodin): $0.39 at Card Kingdom, near mint, their price list as of .
Grab the Reins 
Instant · Uncommon · Mirrodin · #95
Choose one —
• Until end of turn, you gain control of target creature and it gains haste.
• Sacrifice a creature. Grab the Reins deals damage equal to that creature's power to any target.
Entwine {2}{R} (Choose both if you pay the entwine cost.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.39 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2016 | 126 | Uncommon | $0.69 | — |
| Mirrodin | 95 | Uncommon | $0.39 | $3.49 |
| The List | MRD-95 | Uncommon | $0.49 | — |
3 rulings from Wizards of the Coast
- 1 December 2004If you cast this with Entwine, you don’t get priority in the middle of resolution. You can’t steal something, do anything (like attack with it), and then sacrifice it.
- 1 December 2004If you choose the “sacrifice a creature” mode, you choose the target of the damage on announcement, but don’t choose what to sacrifice until resolution. You must sacrifice a creature when Grab the Reins resolves, even if you don’t want to. If you don’t control any creatures at that time, Grab the Reins deals no damage.
- 1 December 2004If you pay the entwine cost, you can sacrifice the creature you gain control of with Grab the Reins.