IMHO, the Switch will launch for roughly $299 US, will immediately sell out upon launch (uh-duh), and will be scarce in most markets throughout 2017 due to a combination of it being the hot new thing and new Zelda + Mario and possibly Pokemon in the same year.  For March-Dec 2017, the Switch will sell as many units as Nintendo can produce... 10m-12m, perhaps?

The big question is 2018 and beyond... can Nintendo keep the momentum up with a continuous stream of titles as well as at least decent 3rd party support, and will it continue to be incredibly popular with general gaming audiences?  If it does, I can see the console (and its multiple variations of course) doing 80+ million lifetime.

If not, then it'll probably do below 3DS numbers, roughly 45-50m max.

For now, I'm going to go right in the middle and say ~60m lifetime.

I'm talking about the New 3DS XL. The regular 3DS XL is available for $125 on Amazon.

80m
As a home console it will have the same appeal of the Gamecube. Maybe even more when they launch it as a stand alone $99 box. As a handheld it will have less appeal than then the 3DS, but that just means tons of return buyers when they announce Switch lite. As a Hybrid It have appeal thar neither the 3DS or Gamecube could manage. As a tablet it'll be very appealing to kids and ve sought after then the 3DS by that demographic.

If you would have meant 1st year sales with that, that would have been the jackpot

LOL

And so many sub-50 million predictions, Wii U really shattered the expectations of many.