Many merchants in Tianjin also take goods from Beijing and Shanghai, but they can't say that they don't take cheap ones, just more than those in Beijing. If you can, you can go to Jewelry Street in Tianjin, and then go to Xidan in Beijing. As you said, it is right to look around more. If you understand it, you can refer to the whole package, but if you don't understand it very well, you'd better buy GIA goods. Go to several stores to compare, and through what they say, you can become an expert after reading it.