Cheapest priced copy (March of the Machine): $0.35 at Card Kingdom, near mint, their price list as of .
Tandem Takedown 
Instant · Uncommon · March of the Machine · #208
Up to two target creatures you control each get +1/+0 until end of turn. They each deal damage equal to their power to another target creature, planeswalker, or battle.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| March of the Machine | 208 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 14 April 2023If the last target is an illegal target as Tandem Takedown resolves, or if both of the first targets are illegal targets, nothing deals or is dealt damage.
- 14 April 2023If one of the two target creatures you control is an illegal target as Tandem Takedown resolves, the other will still get +1/+0 and then deal damage equal to its power.