What has the most copper in it to scrap?

It was a "thing" to do for awhile.  Now, not so much. Now they are cutting out the catalytic converters in newer cars at the tip(not for copper, but for platinum, and 3 other rare earth metals inside them so you need knowledge of metallurgy to know which is which

Why are you collecting granite when diamonds are available?

vacant buildings the water pipes in the walls and the wiring system

does not matter every little bit counts . when you have enough then cash it in 

IDK ANLUT THAT