I wonder what the ideal curve is for this sort of event ingredient to create an interesting market?
Very rare during a finite event?
Common during a finite event?
Start slow to give people a chance to cater to the "gotta have it first" crowd, then have a few weeks where they are fairly common, then return them to being a rare, but persistent drop?
A seasonal spawn? (permanent part of the game, but only for a few weeks each year?)