Even 8k playback is no joke. The price of this to play 4k@60fps games with Ray tracing and 8k video will not be cheap. Add in a proc that can play 8k, uhd drive and what will need to be a lot of ram and sizeable ssd, and we're expensive. Nobody is taking that kind of margin loss to make this $500. Something dramatic would have to happen in the used tech for this to happen at $500
This is why streaming/server farm model is starting to spread. 4k @60fps with Ray tracing requires at least a 2080 and only on will optimized games. That's$700-$800 on the graphic core and associated memory alone.