Cheapest priced copy (Commander Legends: Battle for Baldur's Gate): $7.49 at Card Kingdom, near mint, their price list as of .
Curse of Opulence 
Enchantment — Aura Curse · Uncommon · Tarkir: Dragonstorm Commander · #209
Enchant player
Whenever enchanted player is attacked, create a Gold token. Each opponent attacking that player does the same. (A Gold token is an artifact with "Sacrifice this token: Add one mana of any color.")
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
6 printings · $7.49 to $7.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2017 | 24 | Uncommon | $7.99 | — |
| Commander Legends: Battle for Baldur's Gate | 786 | Uncommon | $7.49 | — |
| Murders at Karlov Manor Commander | 150 | Uncommon | $7.49 | — |
| March of the Machine Commander | 274 | Uncommon | $7.49 | — |
| The List | C17-24 | Uncommon | $7.49 | — |
| Tarkir: Dragonstorm Commander | 209 | Uncommon | $7.49 | — |
5 rulings from Wizards of the Coast
- 25 August 2017Curse of Opulence's triggered ability resolves after attackers have been declared. Any costs to attack must have already been paid before the attacking player creates the Gold.
- 25 August 2017A player is attacking another player if they control a creature that's attacking that player. If no creatures are attacking the enchanted player as a Curse's ability resolves (most likely because they've left the battlefield), only the Curse's controller performs its actions.
- 25 August 2017Each Curse's ability triggers only once, no matter how many creatures are attacking the enchanted player.
- 25 August 2017The triggered ability of these Curses won't trigger if only a planeswalker controlled by the enchanted player is attacked.
- 25 August 2017If you enchant yourself with one of these Curses, you'll get its effects whenever another player attacks you.