Basically for many categories just go into enthusiast spaces. Audiophiles for headphones. Or a boating club for boating equipment.... you get the gist of it 😂

For a few categories the exclusivity to rich people is the point. They charge so much money because customers like that you are excluded. This is true for e.g. art, mosaic craftsmen, jewlery, watches are a famous example, partially in clothes. Real estate is a big one in this category. 🤷🏻‍♀️🤷🏻‍♀️