I want to share my list of sites for buying digital and non-digital goods.

tradekey.com - a lot of useful things, mostly Asian suppliers, I bought Windows and protein there a couple of times. But there is a drawback, it is registration and constant pop-ups.
ec21.com - no pop-ups, very convenient, there are not many products, most suppliers leave contacts in pictures, so it is not necessary to register.
ktnet.com - the site is in Chinese, but you can understand it, it is also convenient, especially if you know Chinese.
Good luck!