Let me give you just one example, not even looking at the cost of waste processing and such, because they don't apply to this story.
A friend of mine is an interesting character, something of a mechanical/electrical genius, he can literally fix any machinery.
One of his jobs involved flying to China to help with the repair of a machine that mass produced latex condoms.
While he was there the proud owner of the condom factory announced he had just finished the creation of a factory for car jacks that were sold in large numbers to the big three car manufacturers for inclusion with their vehicles.
He got a tour of the 'new' factory.
He described a scene straight out of the worst of the beginnings of the industrial age. Workers, mostly women and children stood at endless tables in very bad light operating hand operated machine tools and tool-and-die stamping machines.
Plenty of them were missing fingers or worse, and the pace was literally feverish, the noise deafening.
It was the most unsafe machine shop he has ever seen and he's been in quite a few of them. Now, arguably this is low tech stuff, not comparable with your macbook, and I'd hope that Apple held their suppliers to a higher standard.
But responsible waste management and safety cost a lot of money when you factor them in to the end price of a product, no matter whether it's a nike shoe, a macbook or a car jack.