I just bought them - available for 100 crowns or 500 gold for 7 crumbs.
Let me tell you - they are cheap at any price! They are wonderful!!
In my world, EVERYBODY works! Pets, Mounts, doesn't matter - they all have jobs to do. It was driving me crazy that I would have a Pale Maiden reading a crystal ball and she's off doing who knows what? The crumbs have solved the problem! You can place a single crumb to make a pet/mount stationary or you can create a path for a pet or mount to follow. I LOVE them! One of the best ideas KI ever had!