OK I've fully read the article and I understand 80% of it. I was about to go to bed so I'm not gonna bother with a full (or elegant) translation, but these are the main points of Nikkei.
Let me get this out of the way first, and sorry for highlighting but I'm afraid no one will pay attention otherwise and this thread will reach 200 pages based on nothing:
In no way does Nikkei state that they understand this is the price Nintendo will ask for the Switch. IT IS SPECULATION ON THEIR PART.
These are the arguments for this speculated price from their article:
- Mr. Iwata's once said in the Jan 30 2014 investor meeting when pressed by an investor about how the Wii U failed to take off: "Whether a platform can achieve great market penetration or not depends on its momentum". In other words, the starting price is an deciding factor in the succes of a console. Nikkei follows up by saying that the Switch's starting performance can thus be somewhat predicted based on what Nintendo announces the price will be on Jan 13th.
- Nikkei says that the Super Famicom, Nintendo 64, GameCube, Wii and Wii U all started with a pricing of 25.000 yen. Meanwhile, Sony's PlayStation 4 has already received two price cuts and currently costs 29.980 yen (500GB model). Within the game industry there seems to be a consensus that the Switch will be around 30.000 yen.
- Nintendo CEO Mr. Kimishima has said that "There are no plans to sell [the Switch] at a loss". Within the stock market, an analyst at Rakuten has said: "If we take market penetration in mind, I'd expect around 20.000 yen". Market penetration influences the sales of software > if the Switch is sold at a higher price than 25.000 yen, investors will be wary.
And that's basically it. They also mention that Nintendo has said that not everything about the Switch has been revealed so it is possible that they will reveal another secret about the Switch on Friday. But Nikkei also mentions that "special features" (gimmicks) make third party support difficult and they name the Wii U as an example.
Disclaimer: I am N2 level in Japanese, I don't really read Japanese newspapers and absolutely no financial newspapers like Nikkei. So maybe I'm misenterpreting all of this, in which case I hope anyone with a better understanding of Japanese to correct me. Also maybe Nikkei has a tendency to post things like speculation but in reality they really have sources for this. Idk
Tldr: As far as I can tell Nikkei is just speculating about the price just like everyone of you is on GAF. This isn't a scoop or leak or rumor.