There are some categories of product I'm no longer willing to buy from Amazon: power cables, replacement chargers and batteries being the biggest offenders. They're such a minefield of fakery and shortcuts that are outright dangerous (e.g. UK plugs lacking fuses and with pins the wrong shape/size) that I'd rather have the extra work and expense of going to a local shop where I can inspect what I'm buying.
>power cables, replacement chargers and batteries being the biggest offenders. I've found Anker gear to be consistently solid on all three counts & frankly I trust it more than store bought. If I could even get it - wouldn't know where to start buying a 60W USB hub in a brick & mortar.
I tend to buy a lot of Arduino and RasPi stuff (plus all the fiddly bits) off Amazon, so there are a few sellers on there that I trust to get good "maker" electronics.
Finally - if you're looking for low-cost but good quality DC gear motors - look into TSINY motors. They're a Chinese manufacturer. They have various vendors on Ebay and Amazon; some are almost (or seem like) "direct from the manufacturer", while others are "further down the chain". I can't vouch for any of them - only for the manufacturer itself (I wouldn't have any qualms with dealing direct with them for a large purchase - but I'm just a hobbyist, so that won't happen).