$400 is really expensive for what it is, basically a Mario, Zelda and Splatoon box. They won't sell 10 millions NX a year at this price.
They realistically can't price it more than the current gen, so $300. They priced Wii at $249 and it worked very well for them. The Wii U was priced $300 / $349 and we know the rest.
I expect (hope for them) a 249$ price.







