Oh hai!~
May I suggest increasing the drop rates of King Earthworm and Well Eaten Rabbit Doll, or adding them to the Bunny Land with a lower drop rate, or otherwise increasing the global generation rate of those loots, or reconsidering the number of those loots required to craft the Spot Light, Rainbow Shell and Mystery Wing costumes.
In practice, about 16h (in total) of egg search yielded me about 600 eggs and 16 pieces from them (in my case, 7 worms and 9 dolls). So I believe we can assume that the effective rate of getting those loots is roughly 1 piece per hour, thus the 3 costumes in question would require 150h to make - actually more, as you need 100 dolls... I suppose the point is clear anyway. It also seems unlikely that any meaningful market is going to emerge for those loots at their current rate.
As a side question, are the rates of those specific loots affected by the droprate increasing gear? The above results were obtained with +34% droprate FYI.
