Taobao is a Chinese version of ebay, they don't accept paypal and most foreign credit cards. Payment is the main setback for overseas buyers, agents are needed to buy for them. The agents charge 5-10% fee, since the things in taobao are so cheap, its worth buying despite the extra fees. Shop around for the best agents by comparing the service fee charged, currency conversion rate, delivery and collections.
Taobao has credit ratings for the stores based on customer service, item matching description and shipping time. Some stores take a month to deliver, or the item is of lower quality than described, the ratings will give you a fair idea of the reliability of the vendors.

The chart represents the feedback rating with the golden cup having the highest score.

 

Don't just go for the cheapest price, check the store's ratings too.