Cheapest priced copy (Mirrodin): $14.99 at Card Kingdom, near mint, their price list as of .
Confusion in the Ranks 
Enchantment · Rare · Mirrodin · #87
Whenever an artifact, creature, or enchantment enters, its controller chooses target permanent another player controls that shares a card type with it. Exchange control of those permanents.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $14.99 to $94.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mirrodin | 87 | Rare | $14.99 | $94.99 |
5 rulings from Wizards of the Coast
- 4 October 2004The exchange isn't optional. If there is a legal choice, you must make one.
- 1 December 2004Confusion in the Ranks triggers on itself entering. If an opponent controls an enchantment, exchange Confusion in the Ranks for that enchantment.
- 1 December 2004The permanents are exchanged only if they're both on the battlefield when the ability resolves.
- 1 December 2004The permanents have to share a permanent type both when the target is chosen and when the ability resolves.
- 1 December 2004Even though Confusion in the Ranks triggers only when an artifact, creature, or enchantment enters, the ability can target a land if the permanent entering is an artifact land.