Cheapest priced copy (Guilds of Ravnica): $0.35 at Card Kingdom, near mint, their price list as of .
Thoughtbound Phantasm 
Creature — Spirit · 2/2 · Uncommon · Guilds of Ravnica · #55
Defender
Whenever you surveil, put a +1/+1 counter on this creature.
As long as this creature has three or more +1/+1 counters on it, it can attack as though it didn't have defender.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Guilds of Ravnica | 55 | Uncommon | $0.35 | $0.49 |
| Murders at Karlov Manor Commander | 122 | Uncommon | $0.35 | — |
3 rulings from Wizards of the Coast
- 5 October 2018You put only one +1/+1 counter on Thoughtbound Phantasm each time you surveil, no matter how many cards you looked at when you surveilled.
- 5 October 2018Once Thoughtbound Phantasm has attacked, removing +1/+1 counters from it won't remove it from combat.
- 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.