How much profit do the scrap yards make per pound?

I usually make anywhere from 10% (shred) to 30% on material that I do not process. smaller yards usually make a better percentage than larger ones...but larger yards move such high quantities they make more overall. It is very tricky running a yard, some customers will scam you,prices drop in the market and you are left "holding the bag", and you have to properly evaluate material that is being brought in. This is a very,very competitive business.