Seller rating is important for those who purchase on Aliexpress…The aliexpress uses a system of ranking vendors, free-market style, based on the amount of feedback the seller received. The higher the rank, the greater the amount of sales, and probably more reliable the seller. I advise you to buy with sellers with ranking above 5 medals (sellers with diamond or crown) to avoid problems.
OF course, if you like compare price and sellers, chnprice.com is a good choice, it help you find the best price and sellers at aliexpress.