After thinking about it, I think they'll sell in the 7-8m range.

thats a lot of votes for such few post.

I did 10-11.9M. Though I know right now it is tracking lower than the Xbox One did, I believe interest is higher than the One and the biggest difference is manufacturing. I also feel like the videogame market is overall in a much healthier place than it was in 2014. Especially with Halo arriving this year. If it is good and MS can manufacture more it should preform better than the X1 did.

Edit: For the bonus question...I'm going to say a tie between Fable, Halo: Infinite, and Perfect Dark. I know that Halo: Infinite didn't look astounding graphically, but gameplay wise it looked pretty fun for me. I'm down for an open world Halo. Perfect Dark and Fable were just teaser trailers though, but Playground Games have been consistently great with the Horizon series and The Initiative has a bunch of good talent. I don't own a Series X though, but if they all turn out good maybe I'll buy. 

I guess around 7.0-7.9m, a bit less than Xbox One

The problem is that the Series X is in competition with the PS5 and the Series S is in competition with the Switch (and the PS5 DE). 

And both PS5 and Switch win in their price point.

By "price point" I'm guessing you're referring to the $200 Switch Lite and $400 for the PS5 Digital.

The Switch automatically wins in price, but from what we've seen the standard $300 Switch is the one most people want. They're willing to spend the extra $100 to get HD Rumble, TV Play, and Joy Con controllers.

For PS5 I think most people will want the Disc version since it is $100 more and they will have that option for discs especially since game prices are now going towards $70, and physical games drop in price just after a few weeks. 

The Xbox Series S and X are in a more interesting position. Since there is a $200 gap some will think harder about which one they want. Now I did mention game prices for PS5 going to $70 and the same applies to both Series S and X, but they have GamePass which makes these consoles appealing for consumers on the cheap.

Of course the market will dictate these prices. Of course for the Switch and Switch Lite people are willing to pay $200 and $300 for those systems. Like really think about this, the Switch is going into it's 5th year and has not seen a price drop. Now the question is later when Xbox's and PS5's will sales slow down because the market doesn't want to buy them at those prices? We will find out possibly next year. My prediction is that in 2 years these systems will see a $50 - $100 price drop.

You slightly missed my point but your overal comment is very interesting

I honestly have no idea. Series S throws a wrench into the normal sales predictions. I'll guess 8 to 8.9 million. Series X will fall far behind PS5 in sales due to the digital PS5 being a better deal. But then there's the S which combined with gamepass should capture a chunk of the broke gamer market.

so it's 100m behind ps5

9-9.9m