Cheapest priced copy (Throne of Eldraine Promos): $1.29 at Card Kingdom, near mint, their price list as of .
Robber of the Rich 
Creature — Human Archer Rogue · 2/2 · Mythic · Throne of Eldraine · #138
Reach, haste
Whenever this creature attacks, if defending player has more cards in hand than you, exile the top card of their library. During any turn you attacked with a Rogue, you may cast that card and you may spend mana as though it were mana of any color to cast that spell.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $1.29 to $11.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Throne of Eldraine | 138 | Mythic | $1.79 | $2.49 |
| Throne of Eldraine | 365 | Mythic | $3.99 | $11.99 |
| Throne of Eldraine Promos | 138p | Mythic | $1.29 | $1.99 |
| Throne of Eldraine Promos | 138s | Mythic | — | $4.49Out of stock |
10 rulings from Wizards of the Coast
- 4 October 2019In a multiplayer game, if a player leaves the game, all cards that player owns leave as well. If you leave the game, any spells and/or permanents you control from Robber of the Rich's effect are exiled.
- 4 October 2019If the defending player doesn't have more cards in hand than you immediately after Robber of the Rich attacks, its ability doesn't trigger at all. If that player doesn't have more cards in hand as the ability resolves, the ability does nothing. It doesn't matter if that player has fewer or the same number of cards in hand in between these two times, or if they have fewer or the same number of cards in hand later.
- 4 October 2019The card Robber of the Rich exiles is exiled face up.
- 4 October 2019You can cast the exiled card if the Rogue that attacked is still in combat, if it's left combat, if it's left the battlefield, or even if combat is over.
- 4 October 2019If you cast an Adventure with Robber of the Rich, it's you, not the card's owner, who may cast the creature later.
- 4 October 2019If Robber of the Rich leaves the battlefield, the effect allowing you to cast the exiled card if you attacked with a Rogue continues to apply, even during later turns—as long as you attack with a Rogue during those later turns.
- 4 October 2019Robber of the Rich's effect doesn't change when you can cast the exiled card. For example, if you exile a sorcery card, you can cast it only during your main phase when the stack is empty.
- 4 October 2019An effect that instructs you to “cast” a card doesn't allow you to play lands.
- 4 October 2019Casting an exiled card causes it to leave exile. You can't cast it multiple times.
- 4 October 2019If a creature is attacking a planeswalker, the controller of the planeswalker is the defending player.