Cheapest priced copy (Ravnica: Clue Edition): $0.35 at Card Kingdom, near mint, their price list as of .
Masked Blackguard 
Creature — Human Rogue · 2/1 · Common · Foundations Jumpstart · #459
Flash (You may cast this spell any time you could cast an instant.)
{2}{B}: This creature gets +1/+1 until end of turn.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ravnica: Clue Edition | 115 | Common | $0.35 | — |
| Foundations Jumpstart | 459 | Common | $0.35 | — |
| Core Set 2021 | 113 | Common | $0.35 | $0.49 |