Were can I buy designer brands for a good price in Shanghai or Beijing?

It is best to go to large shopping malls to find good desinger ones and at the pedestrians, you amy find the discount stores for these items.

In Shanghai, you may find at the malls/stores at the Bund and Huaihai Road. Nanjing Road is a good choice to find some with reasonable ones.

In Beijing, Dongdan is a good choice to find nice ones, but they are expensive. At Xidan, you will find the discount ones.