Its not the primers guys, its the small piece of steel inside the primer. The anvil of the primer, althouh small makes it what they call irony brass. Clean Brass was around $3/lb last time I asked, Irony brass is just over a dollar. It pays to knock thoes primers out. A big scrapyard is very particular, They make their money reselling scrap. They can't afford to loose $.10 a lb on somthing as that is probably most of there profit.
I had 300 3/4" brass sprinklers that were wore out and I sold for scrap. If I had taken the time to pull the pin and springs on them the extra money I would have got could have bought a nice rifle. I was stuborn and didn't want to haul them back home.