Cheapest priced copy (Strixhaven: School of Mages): $0.35 at Card Kingdom, near mint, their price list as of .
Emergent Sequence 
Sorcery · Uncommon · Strixhaven: School of Mages · #129
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. That land becomes a 0/0 green and blue Fractal creature that's still a land. Put a +1/+1 counter on it for each land you had enter the battlefield under your control this turn.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Strixhaven: School of Mages | 129 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 16 April 2021The last sentence of Emergent Sequence’s ability counts the land it put onto the battlefield.
- 16 April 2021The land won’t be a creature as it enters the battlefield unless some other effect is making it one. Abilities that trigger whenever a creature enters the battlefield won’t trigger.