FOILCheapest priced copy (The Lost Caverns of Ixalan Commander): $4.49 at Card Kingdom, near mint, their price list as of .
Broadside Bombardiers 
Creature — Goblin Pirate · 2/2 · Rare · Secret Lair Drop · #2410
Menace, haste
Boast — Sacrifice another creature or artifact: This creature deals damage equal to 2 plus the sacrificed permanent's mana value to any target. (Activate only if this creature attacked this turn and only once each turn.)
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
3 printings · $4.49 to $32.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| The Lost Caverns of Ixalan Commander | 54 | Rare | $6.99 | — |
| The Lost Caverns of Ixalan Commander | 86 | Rare | $4.49 | — |
| Secret Lair Drop | 2410 | Rare | — | $32.99 |
5 rulings from Wizards of the Coast
- 10 November 2023If it's not your turn and you gain control of a creature with a boast ability after that creature attacked, you can activate that creature's boast ability if it hasn't been activated yet that turn.
- 10 November 2023If an effect adds additional combat phases to a turn and a creature with a boast ability attacks more than once during that turn, its boast ability can still be activated only once.
- 10 November 2023The back face of a double-faced card doesn't have a mana cost. A double-faced permanent with its back face up has a mana value equal to the mana value of its front face.
- 10 November 2023If a creature with a boast ability is put onto the battlefield attacking, it was never declared as an attacker. Its boast ability can't be activated that turn.
- 10 November 2023A boast ability can be activated at any point after the creature with that ability has been declared as an attacker. This can be before blockers are declared, after blockers are declared but before combat damage is dealt, during combat after combat damage is dealt, during the postcombat main phase, during the end step, or, in some unusual cases, during the cleanup step.