Cheapest priced copy (Streets of New Capenna Promos): $0.49 at Card Kingdom, near mint, their price list as of .
Sanguine Spy 
Creature — Vampire Rogue · 2/3 · Rare · Streets of New Capenna · #93
Menace, lifelink
{1}, Sacrifice another creature: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
At the beginning of your end step, if there are five or more mana values among cards in your graveyard, you may pay 2 life. If you do, draw a card.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $0.49 to $0.69 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Streets of New Capenna Promos | 93p | Rare | $0.49 | $0.49 |
| Streets of New Capenna Promos | 93s | Rare | — | $0.69 |
| Streets of New Capenna | 93 | Rare | $0.49 | $0.49 |
| Streets of New Capenna | 420 | Rare | $0.49 | $0.49 |
6 rulings from Wizards of the Coast
- 29 April 2022The mana value of a double-faced card in your graveyard is always the mana value of the front face.
- 29 April 2022X is 0 when determining the mana value of a card in your graveyard.
- 29 April 2022“Five or more mana values among cards in your graveyard” means there are at least five different mana values among those cards.
- 29 April 2022Sanguine Spy's triggered ability checks the number of mana values among cards you control both when the ability triggers and when it resolves. If you no longer have five or more mana values among those cards when the ability resolves, you may not pay 2 life.
- 29 April 2022The mana value of a split card in the graveyard is the total mana value of both halves of that card. It does not have two mana values.
- 29 April 2022The mana value of a land card is 0.