Cheapest priced copy (Planar Chaos): $0.35 at Card Kingdom, near mint, their price list as of .
Reality Acid 
Enchantment — Aura · Common · Planar Chaos · #45
Enchant permanent
Vanishing 3 (This Aura enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When this Aura leaves the battlefield, enchanted permanent's controller sacrifices it.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
2 printings · $0.35 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Planar Chaos | 45 | Common | $0.35 | $3.49 |
| Time Spiral Remastered | 81 | Common | $0.35 | $0.79 |