[4*, 18k crowns]
Virulisk Suit Recipe
(http://wiki.spiralknights.com/Virulisk_Suit)

[3*, 7k crowns each]
Brute Jelly Mail Recipe, Gunslinger Hat Recipe

[2*, 2k crowns each]
Prismatech Alchemer, Jelly Mail

I'd be willing to the Jelly Mail & Brute Jelly Mail as a combo deal for 8k