
Many of the “factories” you message are trading companies that buy from factories and resell to you. That is not wrong in itself, but it is wrong not to know which party is in front of you.
A trader may suit you when you need varied items in small quantities. But know that they are an intermediary, that their margin is inside the price, and that your control over quality passes through them.
Pick three suppliers you contacted or found pages for. For each write: factory or trader? What is the evidence? What do you still not know?