I guess the home console only Switch (Switch TV), could easily cost $99 as it wouldn't require screen nor battery.

PS2 got down to $99 on April 1, 2009 which is 8.5 years after US launch (and over 9 years after launch in Japan).
For Switch, 8.5 years after launch would be Aug/Sep 2025. Not "starting now".

Besides, $99 in 2009 is around $120 with inflation.

I think MP4 is going to be way bigger than any previous Metroid game. I think the userbase of Switch would eat up Metroid Prime, and Nintendo fans are dying for it. It's not gonna be a mega selling game but 6 to 8 million is very possible I think, which would make it a pretty big game sales-wise. I hope they don't add in multiplayer though. Deathmatch just doesn't fit with Metroid. MP2 had deathmatch, that didn't lead to an explosion in sales, because it just doesn't fit with the series. Also considering the setbacks they've had with development, I definitely don't want them spending a bunch of time trying to add in multiplayer when they need to just be focusing on making the game great and getting it finished.

I'm assuming Metroid Prime Trilogy HD will be released at some point, and before MP4 comes out, and I think that game will also sell more than any other Metroid.

More Pokemon games. Super Nintendo World might boost a little on Japan.

I follow the development of Metroid Prime 4 very closely on information that is publicly available. Job hiring descriptions on Reto Studios' homepage and the people they effectively hired at the end indicate that it will have a strong online multiplayer-mode. They hired people which had leading positions in the Halo, Battlefield and Star Wars series. I'm personally not a big online-player but why would they hire such experts if they wouldn't go with a serious online multiplayer-mode?

They will break 170M. Everybody wants it unconsciously, everybody love it.
If the base Switch is at 250 + 1 game with 3 other models (Lite + Pro + ???), it can still be at 350K/month in 2022.

They should definitely do this. Just as the Lite appeals to gamers who don't want to pay for TV functionality they'll never use, there's a lot of gamers out there who wouldn't mind playing the Switch on a TV but don't want to pay for portable functionality they'll never use.

Assuming a Switch TV does happen, no way is it going to be $100.
If you’re going to have a TV only Switch, then you need a controller. That’s $70-80 right there depending on if Nintendo decides to bundle the Joy Cons or the Pro Controller. Even if you take out all the portable aspects like the screen and the battery, there’s no way that Switch unit costs just $20-30 to manufacture.

Maybe not $100, but $150 shouldn't be out of reach when they've selling the Lite at $200 since last year. By the time a hypothetical Switch TV launches in say mid to late 2021, manufacturing costs should have fallen in the two years since Lite launched.

Yes it about time the Nintendo Switch Regular Model gets a price drop, maybe even Switch Lite before the Switch Pro which i think is Holiday 2021 with BOTW 2.