I haven't looked at what a GPU equivalent would be, but by the time PS5 hits the market, I doubt going to be anywhere near 270$.
As long as there aren't any supply chain disruptions (as there are now).
It appears that the real killer is the hardware-accelerated decompression block pulling the data straight from SSD into CPU/GPU memory in the exact right location/format without any overhead, which isn't available on commodity PC hardware at the moment.
I found some historical price data and I'm surprised - the 2700 really was $150 back in January! Vendors are price gouging the old ones now, and the 3700X is currently $295 on Newegg.
As far as the GPU goes, an 8GB from the 500 series (only 32 CU, released 2017) is still at least $140 today. And noting the memory again, that's 8GB GDDR5 versus (reportedly) 16GB GDDR6 so I'm skeptical the price will fall all that much relative to the 6GB card I mentioned.