If its true that a HD 7770 is somewhat equivalent of a PS4 GPU, then these VGA costs at about R$300,00~400,00:
http://www.kabum.com.br/produto/297...770-1024mb-1gb-ddr5-pci-express-gv-r777oc-1gd
A nice core-i5 you can buy for like R$900,00:
http://www.kabum.com.br/produto/494...-1ghz-3-3ghz-max-turbo-lga-1150-bx80646i54440
8gb Ram Corsair, at about R$350,00:
http://www.kabum.com.br/produto/315...ance-8gb-ddr3-1600mhz-cmz8gx3m1a1600c10-black
Let's say you expend 600 with a cabinet (that's the translation for the PC "case"?) and a motherboard. And you expent at about R$2250,00. And I have not even searched deeply.
Now a PS4 in a gray marketing store that's know for having low prices, almost R$1800,00:
http://www.superrecruta.com.br/playstation-barato/consoles-playstation-barato.html
There's a difference of 450~500. New releases for PS4 costs at about 190, that's less then 3 new games difference.
And I'm not even a PC gamer. I play almost exclusively on consoles, for years. But besides I agree a PC may cost a little more to build a similar PS4/XB1 machine, you will easily take it back on games in a year depending how much you play.
I just don't play on PC cause I don't enjoy it. I prefer the dedicated gaming systems that consoles are and that's all. But PC in a long run is chaper, and you won't expent R$5.000,00 to build a PS4 equivalent machine, that I'm
100% sure. That much you would spent on a high-end machine, if that much.