Treants keep eating the Time Mushrooms, which makes them much more difficult to find.
One Treant in particular, Beltodo, greedily shoves them in his mouth. We have to get rid of him, or he'll cause the mushrooms to go extinct!
You can find him between Seven Star Square and Goddess Lake.
You know how it works - supply and demand. When the mushroom supply goes down, the price of powdered mushrooms skyrockets.
To restore mushroom production, you must kill ancient Treant Beltodo.
Botanists don't make much money - I know, shock of the century. But I can't afford overpriced mushroom powder.