This issue is explained in that video. Taxes are applied over previous taxes. I don't know if it's the same thing, but it's like the "simple interest and compound interest" reasoning. PS4 has a higher base value/price than the 3DS and, when you apply the taxes, that difference upscales greatly. Besides, Nintendo could be subsidizing the 3DS, like MS is doing with the X1 in Brazil and (probably) other territories.
In the end, PS4 has an absurd price in Brazil mainly because of high tax, and because Sony is not subsidizing it (unlike MS with the X1). In my opinion, that's the most reasonable explanation so far.
The reason MS is partially able to subsidize exports to compensate for import taxes/tariffs is because they utilize massive subsidies here in the US courtesy of the US tax-payer via bought-and-paid-for US Congress. The US tax-payer is essentially getting shafted because MS pays little or no taxes here...instead the US middle class has to pony up more so that MS can then justify subsidizing in other countries. Japan based Sony has no such system in place in which they basically own the government and shaft the Japanese citizens in order to compensate for idiotic Brazilian import policies.