Cheapest priced copy (The Lost Caverns of Ixalan): $0.49 at Card Kingdom, near mint, their price list as of .
The Belligerent 
Legendary Artifact — Vehicle · 5/5 · Rare · The Lost Caverns of Ixalan · #225
Whenever The Belligerent attacks, create a Treasure token. Until end of turn, you may look at the top card of your library any time, and you may play lands and cast spells from the top of your library.
Crew 3
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
4 printings · $0.49 to $1.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| The Lost Caverns of Ixalan | 225 | Rare | $0.49 | $0.79 |
| The Lost Caverns of Ixalan | 384 | Rare | $0.69 | $1.49 |
| The Lost Caverns of Ixalan Promos | 225p | Rare | $1.29 | $1.99 |
| The Lost Caverns of Ixalan Promos | 225s | Rare | — | $0.69 |
4 rulings from Wizards of the Coast
- 10 November 2023If the top card of your library has an Adventure, you can cast the Adventure spell this way.
- 10 November 2023If the top card of your library changes while you're casting a spell, playing a land, or activating an ability, you can't look at the new top card until you finish doing so. This means that if you cast a spell from the top of your library, you can't look at the next one until you're done paying for that spell.
- 10 November 2023You must pay all costs and follow all timing rules for spells cast and lands played from the top of your library this way.
- 10 November 2023Once The Belligerent's triggered ability resolves, you can look at the top card of your library whenever you want until end of turn (with one restriction; see below), even if you don't have priority. This action doesn't use the stack. Knowing what that card is becomes part of the information you have access to, just like you can look at the cards in your hand.