Niche items are pretty much a miss on Amazon. I buy a lot of things on Amazon but as a hobbyist cook and knife collector something like whetstones are much better purchased at a specialty retailer. I trust a shop like japaneseknifeimports.com a lot more than Amazon. These shops cater to the community and the mutual success of the community and the businesses are important.
And random components… you’ll have better luck on eBay. Need a P key for you random laptop keyboard, 1000 5mm LEDs or usb-a cable, male on both ends, straight and right-angle? Gonna have better luck on eBay.
And then the actually unique stuff. I’m buying odd lots of used postage stamps. I’m sure as a seller doing one-offs, even if it’s a common item, eBay is the way to go.
Amazon has improved a lot, but eBay still king on that.
That's true, but the problem I mention persists with a lot of normal searches too. Like search for a 3.5mm cable, a USB C dock, or a power bank. You'll get a whole lot of cheap garbage from oddball brands.