Just search for the XFX brand,I think it is the only one available as new in China.A few friends of mine bought in bulk like 25 of them to build their mining rigs.They found them through Alibaba and of course they had a contact in China who sent them the cards,you should NEVER buy through Alibaba without having a contact in China as the risk of getting scammed is really high.
But yes for the other brands most of them you cannot find new anymore.
I've bought cards from Alibaba without any agent in China checking things for me, the truth is always buy from verified sellers and stores, make sure that trade assurance is active so you can get refund if anything happens and also make sure you are buying from sellers that many have bought from and leave good comments