I think Microsoft will be very aggressive with pricing here. They know they screwed up at the start of this generation and PS4 took advantage. MS has a lot more money in the bank than Sony does as well, so I'm going to predict they sell it for a loss ($400) and make up for it with other profits. Heck, with Xbox gold, they could sell for $350 and be fine as long as people buy probably at least 3 games.
Ps5 may be the same price, but Microsoft will advertise itself as more power for the same buck. Sony probably won't be willing to lower their price as much, just a guess.