Budget 21-30k What would be a good price for a used Ryzen 9 5950X?

Apologies if this is the wrong section. But couldn't figure out where else this could go. Mods, request you to please move to the correct section if this is not it.

Anyway, as in the title, what would be a good price for a used 5950X? I'm looking to upgrade from my 5700G.

Also, what would be a good selling price for the 5700G?

Thanks.