This is really a wider issue. If one likes a bargain, things dirt cheap, cheaper than the usual stores, then it's obvious a price is being paid somewhere that isn't pretty. It goes for all that Made In China stuff, Pakistani goods produced by exhausted children, etc etc. And at the top of the pyramid sits a fat man/woman raking it in, oblivious to the sweated labour that made them rich. So, the only way forward is to consider a bit before buying. If it's really cheap and a superb bargain, it's probably not ethically produced. If you go ahead anyway, you're doing your bit to prolong the suffering.

Now, the other side:-

If people stop buying these goods (whether from Amazon, China, or anywhere else) the workers won't be exhausted, they'll be out of work. In some cases this could be a total disaster for them. Their families could truly suffer deprivation and in the developing countries, fragile economies could fold altogether.

The answer? Fairer distribution of wealth, fairer wages, fairer working conditions, fairer prices. How to achieve this? Haven't a clue.