The $100 an item market sounds like fair trade. So you might compete with fair trade and try to explain why your approach is better.
The $50,000 an item market sounds harder but more interesting. I’m not sure I would ever buy a $50,000 hoodie or mug, no matter how much money I had or how nice the designs on them were. But I could see myself (if I was rolling in money and cared about my personal appearance) buying a tailored suit for $50,000, and explaining that it only cost $200 to make (or whatever it really does) and the rest went to charity. You might have to establish your brand in a conventional way (tailored suits, fancy dresses, runway shows, etc.) and be compelling artistically, as well as have the ethical angle. You would probably need both to compete at that level, is my guess.
Honestly at this point the $50,000 item is more like a joke, something to make a point. I’d have a listing there to raise awareness of the fact that people really are spending that kind of money on stupid stuff all the time, which I think is a moral scandal. But of course, I’d be happy if somebody actually bought it! But in any case, although people usually don’t buy t-shirts or hoodies for $50,000, they buy them for a few hundred dollars all the time. This shop idea is largely inspired by this Patriot Act episode: