Dunno... maybe 2-3x markup at most? Obviously removing the child and quasi slave labour from the production process.

Both, remove human labor in the process of making clothes altogether and have it produced cheaper.

Most clothes are complex items and the manufacture of them is very unlikely to ever be fully automated within a reasonable time frame (such as our lifetimes). People will always be a part of the process. Many tasks are just too expensive to automate vs a cheap labourer.

Clothes should be like many other things: cost more, have better quality, longer lifespans and have less negative impact on those who produce them and the environment where they are produced & recycled.

I read his comment as "I hate the 1000% markup on clothing"

Oh I do too.

But there's two separate approaches for people who hate that markup: lowering the markup or increasing the production cost. Given current industry standards, I think the second approach is reasonable. It's also very easy to do, if you can afford to.