Be very careful when using Alibaba, there are a lot of people on there very keen to take money from you but less keen sending you products. Since their stock market listing Alibaba have apparently made efforts to clean up their portal but I would recommend an extremely cautious approach.
As a person who teaches safe sourcing practice I can completely agree with what quikshop has written.
I also agree with what Shane S2S had said about middlemen on Alibaba adding to your cost without giving you any advantage.
One of my book readers who is a very astute businesswoman with years of experience in the hairdressing industry told me that the human hair industry is one of the most corrupt business areas she has ever found. Also, just today as it happens another one wrote that he had given up handling hair extensions because the market is saturated and many suppliers are "here today and gone tomorrow.". Maybe you might consider a different product area for your business.
Regarding sourcing in general, I advise against using Alibaba and the other big B2B portals mainly because their verification procedures are woefully inadequate, including the fact that they allow thousands of traders to masquerade as manufacturers.
Whatever you are sourcing, it can be done safely from home if you learn the principles of safe sourcing. Unfortunately most newbies tend to regard buying overseas as just like buying locally, and they go into it totally unprepared. A large number of newbies complain that they don't even get a reply when they first contact potential suppliers, but that is because they have shown the supplier too clearly that they are newbies.
You don't need to learn all the rules and regulations about importing, but you do need to know the basics of shipping methods and payment methods, as well as how to identify real manufacturers, how to negotiate small orders even if they quote big MOQs, and how to be sure you are getting the best prices.
If you are determined to visit China for sourcing purposes, you must do your preparation. This will involve narrowing down the number of potential suppliers to a manageable number within a manageable territory and arranging in advance to visit them.
You can do this online, but it should not be rushed. Even before you visit them you must build a relationship with them so that they will regard your visit seriously.