I have gone to 4 fish stores in the area. Southern Aquatics, Pure Reef, The Fish Store, and Atlanta Aquarium(not to be confused with Georgia Aquarium). And I have not seen that at any of those stores. I also haven’t seen many toadstools in generally. Which is sad because I think they look very cool. Maybe they are becoming less popular overall I can’t say for sure. What I would do is go to your lfs and ask them if they can order it from their supplier because they get shipments in all the time. Happy reefing!
-John