Cheapest priced copy (Guilds of Ravnica): $0.35 at Card Kingdom, near mint, their price list as of .
Dimir Spybug 
Creature — Insect · 1/1 · Uncommon · Murders at Karlov Manor Commander · #206
Flying
Menace (This creature can't be blocked except by two or more creatures.)
Whenever you surveil, put a +1/+1 counter on this creature.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Guilds of Ravnica | 166 | Uncommon | $0.35 | $0.79 |
| Murders at Karlov Manor Commander | 206 | Uncommon | $0.35 | — |
2 rulings from Wizards of the Coast
- 5 October 2018You put only one +1/+1 counter on Dimir Spybug each time you surveil, no matter how many cards you looked at when you surveilled.
- 12 January 2024An ability that triggers "whenever you surveil" triggers after you're done surveilling, even if you have fewer cards in your library than the number of cards you're instructed to surveil. It even triggers if you have no cards in your library.