Update: I think I'll just go with it. Maybe exchange/sell it later ;)
And thank you for your advice. I can't find a cheep and reliable marketplace for an old 3090 in China.
Our school provide some V100s on cluster, it may be tricky but able to run some program.
Not sure where you are located. If you're lucky enough to live in the US by a Microcenter computer store they often have refurbished NVIDIA cards for very reasonable prices. I picked up a 3090 for $699.
The consensus is that AMD cards work, but software support is pretty finicky. For my part, even if I wanted an AMD card, I'd either look for a great deal or wait until new nvidia cards just because they will likely push older card prices down. If you don't mind the headaches and papercuts of the software almost working.