I bet US$ 449,00 for a basic model and US$ 549 for a premium version. But that's just wishful thinking, the safest bet is what the OP said.

Starting from 499$/499€

Even $499 is a bit high, considering the economical moment the world is living. 

I wonder if Sony and MS are willing to take losses to have launch prices lower. 

If the BOM is truly $450, then at $500 they would either be breaking even or possibly making a slight profit.  $449 is not impossible.  Hell, $399 isn't impossible if Sony wants to take a $75-$100 loss to help ensure next gen is in the bag.

If anything, history shows that Sony is the one willing to take the loss, not MS.  Even just as recently as this gen, MS wouldn't drop the price of the XBO, even though the $499 price was killing it, until they could get BOM to a point where they were breaking even without the Kinect.  Then, they could have ended this gen with a bang with a $399 XBO X, but chose not to lose money on the HW.  Xbox is just not as important to MS as PS is to Sony.  Sony NEEDS PS5 to succeed, even if it means taking a hit at the beginning.  MS could just drop Xbox HW tomorrow and not bat an eye.

No, they couldn't. 399$ XBO X wouldn't really have changed that much for how this gen ended up. It was already too late for MS to win some significant marketshare back by having a price parity with Sony on a niche mid gen refresh side. They could have made some great critically acclaimed first party games instead and it would have made even more difference than selling this niche console for 399$.

The current CEO has a background in streaming/online services. He sees the value in streaming games and GAAS. Series X is an attempt to use the Xbox brand to help bring those services, mainly xCloud. Even when buying those studios, MS said it was more about adding content for GamePass and, in the future, xCloud, not to sell Xbox HW.

I wasn't speaking just about the PS3. Sony has always sold at a loss. And they have learned from the PS3. Taking a $50-$100 loss, with a constant stream of PSN money coming in, is not the same as taking a $300 loss with no PSN money.

Your logic is also backwards in your original post. If a company doesn't care as much for a product, they are less likely to take a loss on it. Not more.

Yes, they could. Everybody keeps talking about the money MS is willing to throw around to win the console war, yet we don't see it happen. MS could have priced the XBO at $399, even with Kinect, but didn't. Hell, without it, they could have gone to $299, but didn't.

Sure, a $399 XBO X wouldn't have won them the gen, but it would have, in combination of more games coming out, allowed them to end the gen with a bang and get people excited for next gen. Like Sony did with PS3. Instead, they slowed game production down, refused to 5ake a loss on the X, and gave a "please be excited" announcement for next gen.

MS is not about losing money on Xbox HW, anymore. They did it to try and enter the market, but it didn't work. Their loses during the 360 era had much more to do with RROD, not actually losing money on each unit sold. And this gen, they didn't take a loss on HW. I don't see them doing it next gen, either, when they are more focused on gaming services than gaming HW.

I just want to remind you that we are talking about delusional MS that was 100% certain they can sell 200m Xbones at 500$ here. As for 399$ XBO X they could but what's the point doing it 4 year in the gen when everything is said and done already. 

Using that logic, Sony should have packed it in with the PS3 and just got ready for next gen. Instead, they started pumping out game after game and dropped the price to $299. This is what helped them recover from their initial stumble, eventually beating the 360, and springboarded them into a strong next gen.

Just further proof, PS is much more important to Sony than Xbox to MS.