Cheapest priced copy (Lorwyn Eclipsed Commander): $0.35 at Card Kingdom, near mint, their price list as of .
Smokebraider 
Creature — Elemental Shaman · 1/1 · Common · Lorwyn · #189
{T}: Add two mana in any combination of colors. Spend this mana only to cast Elemental spells or activate abilities of Elementals.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
4 printings · $0.35 to $7.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Lorwyn Eclipsed Commander | 96 | Common | $0.35 | — |
| Planechase | 66 | Common | $0.35 | — |
| Lorwyn | 189 | Common | $0.35 | $7.99 |
| Modern Masters 2015 | 125 | Common | $0.35 | $0.99 |
3 rulings from Wizards of the Coast
- 1 October 2007The mana can't be spent to activate activated abilities of Elemental sources that aren't on the battlefield.
- 1 October 2007You can use this mana to pay an alternative cost (such as evoke) or additional cost incurred while casting an Elemental spell. It's not limited to just that spell's mana cost.
- 1 October 2007The mana can be two mana of the same color, or one mana of each of two different colors. The mana can't be colorless.