If there’s no products on Amazon for “High end” then you have no Amazon products to promote and no way on earning any commission. Why not try keywords like Best (x) or Luxury (y) where there will be more search volume. Let’s say you want to promote hammocks, you can then target search KWs such as Best Hammock for Under $100, Most Comfortable Hammock, Luxury Hammocks etc. Let me know how you get on.
Education occurs most often in "real life" by becoming involved and learning the details as time progresses. Although there are several books on the topic, some so-called "how-to" or "silver bullet" books instruct readers to manipulate holes in the Google algorithm, which can quickly become out of date, or suggest strategies no longer endorsed or permitted by advertisers.
A page or notice on your website or blog that makes your site visitors aware if you are being paid or compensated (via affiliate marketing or any other methods) for any purchasing recommendations or product or service endorsements you make on your site. A disclosure is required if you're doing affiliate marketing to be in accordance with FTC laws. You'll find more on that here.
For example, if I talk about how cool a product is, and then you find out that I’m an affiliate for them, wouldn’t you as a conscientious observer become skeptical as to whether my information is biased, if perhaps I’m only saying how cool something is because I can get paid for it? Wouldn’t that make you question my integrity with other things I say as well?
Always disclose your affiliations. Your readers will appreciate your honesty and will feel better about contributing to your earnings. If they sense that you are being less than honest about your affiliations, they are savvy enough to bypass your link and go directly to the vendor just to avoid giving you referral credit (even though the price is the same it's just something people do; strange but true!).