No need to ask, just use the Ice Mushroom. Ice Mushroom gives you bricks and stones, but you can't buy them. I've been playing this game for more than 3 months, and I haven't even seen a fragment of Ice Mushroom (challenges, treasure chests, Penny). The most is Pan. Ni's shop has sold ice mushroom decoration fragments for 30 bricks, damn. Not to mention the Flame Mushroom, the garden exchange is already at level 4.