Cheapest priced copy (Commander 2011 Oversized): $2.29 at Card Kingdom, foil, near mint, their price list as of .
Riku of Two Reflections 
Legendary Creature — Human Wizard · 2/2 · Mythic · Double Masters · #214
Whenever you cast an instant or sorcery spell, you may pay {U}{R}. If you do, copy that spell. You may choose new targets for the copy.
Whenever another nontoken creature you control enters, you may pay {G}{U}. If you do, create a token that's a copy of that creature.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
4 printings · $2.29 to $13.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 214 | Mythic | $7.49 | $12.99 |
| Commander 2011 | 220 | Mythic | $7.99 | — |
| Judge Gift Cards 2014 | 3 | Mythic | — | $13.99 |
| Commander 2011 Oversized | 220 | Mythic | — | $2.29 |
10 rulings from Wizards of the Coast
- 22 September 2011If the copied spell is modal (that is, it says “Choose one —” or the like), the copy has the same mode as the original spell. You can't choose a different one.
- 22 September 2011The copiable values of the token's characteristics are the same as the copiable values of the characteristics of the creature it's copying.
- 22 September 2011If the creature had {X} in its mana cost, X must be 0. Note this is different from an {X} found in the mana cost of a copied spell.
- 22 September 2011If the creature that caused Riku's second ability to trigger has already left the battlefield by the time the ability resolves, you can still pay {G}{U}. If you do, you'll still put a token onto the battlefield. That token has the copiable values of the characteristics of that creature as it last existed on the battlefield.
- 22 September 2011If the copied spell has {X} in its mana cost, the value of X is copied.
- 22 September 2011Each time the first ability triggers, you can pay {U}{R} only one time to get one copy of the spell. Each time the second ability triggers, you can pay {G}{U} only one time to get one token.
- 22 September 2011As the token is created, it checks the printed values of the creature it's copying, as well as any copy effects that have been applied to it.
- 22 September 2011If the spell that caused Riku's first ability to trigger has left the stack by the time the ability resolves, you can still pay {U}{R}. If you do, you'll copy the spell as it last existed on the stack.
- 22 September 2011You can't pay any additional costs for the copy. However, effects based on any additional costs paid for the original spell are copied as though those same costs were paid for the copy. Notably, if the original spell was kicked (or kicked a certain number of times), the copy will also be kicked (or kicked that many times).
- 22 September 2011Riku's first ability triggers whenever you cast any instant or sorcery spell, regardless of whether that spell has targets.