not to come off rude here but...whatever someone is willing to pay for it. Also depends what "used" condition they are in. Do the joints need a rebuild, add-a-leafs sag fast, blocks for the back also(do not get the group started on that debate), how are the rubber bushings, that style disc can be a pain to connect and disconnect(personal opinion there), etc,etc. So knowing that what are YOU willing to pay, and what are they asking for for the used kit and is it complete or are things missing? Let us know your budget and we may have some other/better options for you.