A bit late, but Sony has offered an explanation:
Brazil's massive tariffs are the issue (or, at least, 63% of it).
Apparently the Xbox One is able to get around this because Microsoft has a manufacturing facility in Brazil, so their console isn't slapped with the tariffs.
Wrong. Both Sony and MS has facilities on Brazil. None of them will produce before 2014 (as I previous believed).
The tax explanation of Sony was not real at all.
http://www4.receita.fazenda.gov.br/simulador/ This is the official tax simulator from brazilian governament. If we put USD 399 plus shipping (total USD 450) there we get this:
R$978.21 - Value on national Coin
R$195.64 - Import tax
R$586.93 - Industrialized good tax
R$16.14 and R$74,34 - "Social" taxes
Total: R$ 1851.26
Then come the state tax, that no corporation pay it in full (due to the rules of this tax), but even if we put the full tax from the most expansive state we get:
1851.26 + 16% * (1851.26) =
2147.46
R$ 2147.46 is near of the 2200.00 that Xbox One cost here on credit card. If you pay with cash you can get a xbox one for around R$ 1950,00
Sony is charging 3999, so they are stealing
1851.54 (USD 852.30) from us.
Also, If an individual (person, not corporation) buy a PS4 on eBay or somewhere else that ship to Brazil and pay all the taxes, the final value is "only" USD 736.