What to do with a dead will-o-wisp?

At the end of the last session, the party recovered the remains to the defeated and dead Will-O-Wisp.  Black and furry.  About the size of volleyball.  Limp and lifeless, with stubby tentacles spread over it in an asymmetrical pattern. 

The players asked at the time what the value of this corpse might be, and I wasn't prepared with a good answer.  But I think I have an answer now that fits into the mechanics of the game.

The oils of the Will-O-Wisp make fine material components.  The possess the properties of rare herbs (used in Nature-based rituals), alchemical reagents (usef for arcane rituals), and mystic salves (used for healing rituals).  (See page 300 of the PHB for a discussion of material components for ritual magic).

The value of this is 300 GP in material components, used for Arcane, Nature, or Heal rituals.