I saw this in Shenzhen today too. how much did you pay for it ?
I bought it when btc price was 16k+, so it was high. Total rmb 19200+650 for the Bitmain psu. Plus I paid 7% tax when I brought it back into my country.
Now Im selling because I rarely mine, and its selling at a loss. Not to mentioned I have to pay for shipping.
Oh well, learning curve for me.