Maybe $8 in materials, but what about Research (hundreds of hours), Development (hundreds of hours), and Testing (hundreds of hours).... maybe a million dollars spent getting one product to market... but all you see is $8 in plastic and metal? At $400 each, the first 2500 products sold just cover the cost, zero profit. That's 2500 customers that get support, free replacements, etc. without Apple having actually made any money. The next 2500 start to finance this post-sale cost, and so it goes.