Cheapest priced copy (Streets of New Capenna Promos): $2.29 at Card Kingdom, near mint, their price list as of .
Cut Your Losses 
Sorcery · Rare · Streets of New Capenna · #410
Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Target player mills half their library, rounded down.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $2.29 to $4.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Streets of New Capenna Promos | 38p | Rare | $2.29 | $3.49 |
| Streets of New Capenna Promos | 38s | Rare | — | $4.49 |
| Streets of New Capenna | 38 | Rare | $2.29 | $2.49 |
| Streets of New Capenna | 410 | Rare | $2.49 | $2.99 |
5 rulings from Wizards of the Coast
- 29 April 2022If you pay the casualty cost of a spell, the copy will resolve before the original spell.
- 29 April 2022You may sacrifice only one creature to pay a spell's casualty cost, and you copy the spell only once.
- 29 April 2022The copy of the spell is created on the stack, so it's not “cast.” Abilities that trigger when a player casts a spell won't trigger.
- 29 April 2022Casualty N means “As an additional cost to cast this spell, you may sacrifice a creature with power N or greater.” and “When you cast this spell, if a casualty cost was paid for it, copy it. If the spell has any targets, you may choose new targets for the copy.”
- 29 April 2022If you cast Cut Your Losses and copy it targeting the same player, that player will mill half their library, then mill half of what remains after that. They do not mill their entire library.