Cheapest priced copy (Outlaws of Thunder Junction Commander): $3.99 at Card Kingdom, near mint, their price list as of .
Cunning Rhetoric 
Enchantment · Rare · Commander Masters · #864
Whenever an opponent attacks you and/or one or more planeswalkers you control, exile the top card of that player's library. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast it.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
4 printings · $3.99 to $4.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2021 | 38 | Rare | $4.49 | — |
| Commander 2021 | 365 | Rare | $4.49 | — |
| Commander Masters | 864 | Rare | $4.49 | — |
| Outlaws of Thunder Junction Commander | 129 | Rare | $3.99 | — |
3 rulings from Wizards of the Coast
- 16 April 2021You'll still pay all costs for a spell cast this way, including additional costs. You may also pay alternative costs if any are available.
- 16 April 2021You must follow the normal timing permissions and restrictions for the exiled card. If it's a land, you can't play it unless you have land plays available.
- 16 April 2021If you play a card this way, it leaves exile and becomes a new object. If it returns to exile later in the turn, you can't play it again.