Hi cnshow,
Group buying is actually a great way for buyers to purchase the products they want or need without too much pressure on the required capital or volume of products to make the purchase. In fact we often see posts by member inviting other members (especially from the same country) to do group buys or group ship certain products to save on the cost.
After a thorough review of the site you mentioned, here are a couple good points I was able to colllect:
1. The site offers FREE membership for buyers and sellers alike.
2. Also accepts PayPal which is considered a safe payment method.
But personally I would not recommend this site. I mean no offense. Here are a few of the reasons why I would not recommend the site just yet:
1. The site is still quite new. The site age does not meet the ideal criteria for it to be considered a safe/secure marketplace. FYI, the site was created just last February of this year. Ideally a site should have been online for at least 2 years.
2. Although the site offers a wide range of product categories, most categories either have only 1 product listed or no products at all.
3. There is no contact page/details such as email address or telephone number provided on the site. Not even a physical address is provided. So how will customers contact you if they have problems?
4. It's also quite hard to understand the policies, rules, FAQ section as the English translation is done quite poorly. Correct grammar is actually a big factor in convincing customers to buy from you or use your site since they will need to understand these details beforehand.
Hope that helps. Cheers :)