Cheapest priced copy (Onslaught): $0.39 at Card Kingdom, near mint, their price list as of .
Chain of Plasma 
Instant · Uncommon · Onslaught · #193
Chain of Plasma deals 3 damage to any target. Then that player or that permanent's controller may discard a card. If the player does, they may copy this spell and may choose a new target for that copy.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.39 to $3.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Onslaught | 193 | Uncommon | $0.39 | $3.99 |