Why aren’t there many used cables on the market?

We know good cables are extremely expensive and used cables would seem a good thing to buy.

My dealer never has used cables and also conveyed to me that the more expensive cables carry profit margin of 80%.

So $5000 cables yield a.profit for both manufacturing dealer by $4000. Was stated that these cables arent bought very often. Mostly the cheaper cables between 400 and 900 are purchased.   
Obviously not a lot of money selling used cables and I think manufacturers may not allow their dealers to sell used cables.