Cheapest priced copy (Planar Chaos): $0.35 at Card Kingdom, near mint, their price list as of .
Lavacore Elemental 
Creature — Elemental · 5/3 · Uncommon · Planar Chaos · #103
Vanishing 1 (This creature enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a creature you control deals combat damage to a player, put a time counter on this creature.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Planar Chaos | 103 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 1 February 2007If Lavacore Elemental deals combat damage to a player, it triggers its own ability.
- 1 February 2007If multiple creatures you control deal combat damage to a player, Lavacore Elemental’s ability triggers that many times.