Cheapest priced copy (Murders at Karlov Manor Commander): $0.49 at Card Kingdom, near mint, their price list as of .
Obscuring Aether 
Enchantment · Rare · Dragons of Tarkir · #194
Face-down creature spells you cast cost {1} less to cast.
{1}{G}: Turn this enchantment face down. (It becomes a 2/2 creature.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.49 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dragons of Tarkir | 194 | Rare | $0.59 | $0.99 |
| Murders at Karlov Manor Commander | 179 | Rare | $0.49 | — |
2 rulings from Wizards of the Coast
- 25 February 2015Obscuring Aether has no effect on spells that instruct you to manifest cards.
- 25 February 2015Note that Obscuring Aether doesn't have a morph cost. Once it's turned face down, it doesn't have a way to turn itself face up.