Cheapest priced copy (Conspiracy): $0.35 at Card Kingdom, near mint, their price list as of .
Flowstone Blade 
Enchantment — Aura · Common · Stronghold · #83
Enchant creature
{R}: Enchanted creature gets +1/-1 until end of turn.
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Conspiracy | 143 | Common | $0.35 | $0.49 |
| Stronghold | 83 | Common | $0.35 | — |