Hopefully they will go for 499$, but looking at PS4, VR and Pro successes, I strongly doubt they will go a single dollar above 399$. They will again want to create as big user base as possible, especially that Sony doesn't plan to offer their games/services on other platforms like MS does, so every PS5 sold will matter more than ever. The way I see the next-gen consoles models will look like is as follows:
XB2S - 299$, 8-12GB RAM, 6-7TF GPU, FullHD
PS5 - 399$, 12-16GB RAM, 8-9TF GPU, CBR 4K
XB2X -499$, 16GB RAM, 10-12Tf GPU, 4K
All will share the same Ryzen CPU, more or less.
How so? If one console will target 1080p with just weaker GPU and lesser memory I see no reason why it wouldn't be able to play games the 4K-focused console will. If Pro and X1X can play the base models games, then there's no reason next-gen games build from the ground up