Assuming I'm correctly understanding how this event works.

Buying invites to the Margrel fight for 200,000 crowns each. ^^

This is how I would prefer to complete this transaction:
-You show me that you have a Book of Dark Rituals and I'll give you 50,000 crowns first.
-You'll summon Margrel.
-After the party receives Wicked Whisker I'll pay you the remaining 150,000 crowns.

Mail me or post here if interested~
IGN: Extra-Salty

Thank ya~

*Not sure if 200,000 crowns is an appropriate price. I'll adjust it if need be.