It always depends. Since they are sellers selling their wares through Amazon the quality can always differ. So far, I have only gotten exactly what they have advertised as far as item quality and condition has been concerned in regards to used books and movies. Just be sure to double-check the feedback and everything else before making a purchase and you should be alright most of the time.
Personally, sometimes the used section can be a miracle and other times you can find even lower prices elsewhere. But, hey, I can't complain. Nothing like picking up books for FRACTIONS of a penny on the dollar.