One thing I have learned about Audiobooks is to listen to the samples before buying. I only like narrators that are voice actors. If the narrator does the same voice for every character I am not going to pay or waste a credit on it. I'll read the ebook.
Another reason to listen to samples is quality. I bought Spider's Bite by Jennifer Estep which is a Urban Fantasy title. 5 Stars by the way!
It had excellent quality and love the narrator's voice but it's sequel Web of Lies which I bought turned out to be very tinny and made the narrator sound different. Maybe I'm picky but if I am going to pay $20+ for an audiobook I want it to sound good.