Cheapest priced copy (Duel Decks: Jace vs. Vraska): $0.35 at Card Kingdom, near mint, their price list as of .
Agoraphobia 
Enchantment — Aura · Uncommon · Duel Decks: Jace vs. Vraska · #22
Enchant creature
Enchanted creature gets -5/-0.
{2}{U}: Return this Aura to its owner's hand.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Jace vs. Vraska | 22 | Uncommon | $0.35 | — |
| Gatecrash | 30 | Uncommon | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 24 January 2013Agoraphobia's last ability can be activated only while it's on the battlefield.
- 24 January 2013Players don't have priority to cast spells and activate abilities between combat damage being assigned and being dealt. This means that if you want to return Agoraphobia to its owner's hand before combat damage is dealt, you must do so before combat damage is assigned (and the creature will no longer get -5/-0).
- 24 January 2013Only Agoraphobia's controller can activate its last ability, no matter who controls the creature Agoraphobia's attached to.