Aliexpress or dhgate, these are 2 largest platforms in China, but the price is expensive, beacuase the sellers need to pay a lot of fees to Aliexpress or Dhgate, you can search buy replica shoes on google, then you can find many websites sell replica shoes, they are cheap price, for example this website:
stockxshoes.com, Yeezy, Air Jordan sneakers, hope this can help you.