Given how China is clamping down on bitcoins mining, there must be lots of used gpu for sell in China.
Anyone know how to buy them? Alibaba?
My recommendation, don't waste your money because while prices have dropped, they still charge a premium for these non LHR cards. If you are looking to buy used GPUs, I deduce that you are trying to save money. But the problem is, (1) warranty for this cards are questionable, i.e. may not have warranty, and, (2) don't know how overused these cards are. Some miners I know just whack the cards for few months then sell them off. Usually cards sold directly from AIB partners to miners don't come with the usual retail warranty, and a lot shorter because they want to make the money and don't want to be responsible for cards that are ran out of what they are build for, i.e. gaming.
FYI, I recently bought an Inno3D RTX 3070 Ti which I shared on the RTX 3000 chat. The card came with a big yellow sticker sealing the card in the anti static bag. The sticker have this big warning message on it saying, "ATTENTION. This product is not designed for Crypto Mining. We reserve the right to void the warranty if there is any damage associated with this application. " I am not sure if they can enforce it, but is just an FYI in case you want to buy a used mining card.