Cheapest priced copy (Dragons of Tarkir): $0.35 at Card Kingdom, near mint, their price list as of .
Qarsi Deceiver 
Creature — Snake Wizard · 0/4 · Uncommon · Dragons of Tarkir · #71
{T}: Add {C}. Spend this mana only to cast a face-down creature spell, pay a mana cost to turn a manifested creature face up, or pay a morph cost. (A megamorph cost is a morph cost.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dragons of Tarkir | 71 | Uncommon | $0.35 | $0.49 |
4 rulings from Wizards of the Coast
- 25 February 2015Megamorph is a variant of the morph ability. You can find more information on morph on cards with morph from the Khans of Tarkir set.
- 25 February 2015Turning a face-down creature with megamorph face up and putting a +1/+1 counter on it is a special action. It doesn’t use the stack and can’t be responded to.
- 25 February 2015The mana produced by Qarsi Deceiver can’t be used to cast a spell that instructs you to manifest cards.
- 25 February 2015If a face-down creature with megamorph is turned face up some other way (for example, if you manifest a card with megamorph and then pay its mana cost to turn it face up), you won’t put a +1/+1 counter on it.