Cheapest priced copy (Battle for Zendikar): $0.49 at Card Kingdom, near mint, their price list as of .
Herald of Kozilek 
Creature — Eldrazi Drone · 2/4 · Uncommon · Battle for Zendikar · #205
Devoid (This card has no color.)
Colorless spells you cast cost {1} less to cast.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.49 to $7.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Battle for Zendikar | 205 | Uncommon | $0.49 | $7.99 |
10 rulings from Wizards of the Coast
- 25 August 2015Herald of Kozilek's last ability can't reduce the amount of colored mana you pay for a spell. It reduces only the generic component of that mana cost.
- 25 August 2015If there are additional costs to cast a spell, or if the cost to cast a spell is increased by an effect, apply those increases before applying cost reductions.
- 25 August 2015Cards with devoid use frames that are variations of the transparent frame traditionally used for Eldrazi. The top part of the card features some color over a background based on the texture of the hedrons that once imprisoned the Eldrazi. This coloration is intended to aid deckbuilding and game play.
- 25 August 2015Other cards and abilities can give a card with devoid color. If that happens, it's just the new color, not that color and colorless.
- 25 August 2015If a card loses devoid, it will still be colorless. This is because effects that change an object's color (like the one created by devoid) are considered before the object loses devoid.
- 25 August 2015The cost reduction can apply to alternative costs.
- 25 August 2015If a colorless spell you cast has {X} in its mana cost, you choose the value of X before calculating the spell's total cost. For example, if that spell's mana cost is {X}, you could choose 5 as the value of X and pay {4} to cast the spell.
- 25 August 2015A card with devoid is just colorless. It's not colorless and the colors of mana in its mana cost.
- 25 August 2015Devoid works in all zones, not just on the battlefield.
- 25 August 2015Herald of Kozilek's last ability doesn't change the mana cost or mana value of any spell. It changes only the total cost you actually pay.