If your big issue is just getting back into mainstream support, you can try looking for a 7600, since RDNA 3 is just one generation removed from the latest. You’ll have to undervolt or limit power and you’ll be stuck with 8GB on that budget but you’ll probably receive software support for slightly longer than the RDNA 2 6600/6700.

What is your current card? The RX 6600 is comfortably within your requirements but has just 8GB of RAM, and the RX 6700 is just at the edge or slightly outside of your budget with 10GB of ram, which you could probably make work if you find a good deal and undervolt it. On Nvidia’s side there’s the 3050 8GB and 3060 12GB.