Cheapest priced copy (Nemesis): $4.49 at Card Kingdom, near mint, their price list as of .
Aether Barrier 
Enchantment · Rare · Nemesis · #27
Whenever a player casts a creature spell, that player sacrifices a permanent of their choice unless they pay {1}.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $4.49 to $27.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Nemesis | 27 | Rare | $4.49 | $27.99 |