The rotor is mounted lenght wise and feeds the incoming grain around the total diameter of the concave giving it more capacity unlike a CASEIH that forces all the grain through the bottom of the concave causing a force feed condition and a high wear condition.As far as to the price of a good used one,I have no idea,you will have to get a hold of a dealer to find out.I know of a good one in Yorkton Saskatchewan his phone number is 306-783-2442,ask for Frank.