Cheapest priced copy (Chronicles): $0.99 at Card Kingdom, near mint, their price list as of .
Chromium 
Legendary Creature — Elder Dragon · 7/7 · Rare · Legends · #224
Flying
Rampage 2 (Whenever this creature becomes blocked, it gets +2/+2 until end of turn for each creature blocking it beyond the first.)
At the beginning of your upkeep, sacrifice Chromium unless you pay {W}{U}{B}.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
4 printings · $0.99 to $79.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Chronicles Foreign Black Border | 74 | Rare | — | — |
| Chronicles | 74 | Rare | $0.99 | — |
| Legends | 224 | Rare | $79.99 | — |
| Secret Lair Drop | 1068 | Rare | — | $5.49 |