Cheapest priced copy (Marvel Super Heroes Commander): $0.49 at Card Kingdom, near mint, their price list as of .
The Squadron Sinister 
Legendary Creature — Human Villain · 5/5 · Rare · Marvel Super Heroes Commander · #417
Flying, haste
Other Villains you control get +2/+2 and have flying and haste.
Mayhem {3}{U}{R} (You may cast this card from your graveyard for {3}{U}{R} if you discarded it this turn. Timing rules still apply.)
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $0.49 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Marvel Super Heroes Commander | 96 | Rare | $0.49 | $0.49 |
| Marvel Super Heroes Commander | 417 | Rare | $0.99 | — |