Silicon wafers (cheap ones) cost about $150/kg. Polysilicon (good luck making a wafer out of it) costs about $30/kg (market has crashed). Copper costs about $7.

Silicon wafers (cheap ones) cost about $150/kg. Polysilicon (good luck making a wafer out of it) costs about $30/kg (market has crashed). Copper costs about $7.50/kg.