I don't listen to a lot of audio, but I have listened to Wild Magic by Tamora Pierce (Fantasy) -- it happens to be on sale for $1.99 this week at Apple (I had the CDS, but I assume it's the same recording produced by Full Cast Audio):
https://itunes.apple.com/us/app/id999121797
The others in the series have also been marked down from 24.99 to 9.99: WOLF-SPEAKER, EMPEROR MAGE, and REALMS OF THE GODS.