You think 350k copies were sold on other PC services than Steam? I'm certain that's impossible. Also Steamspy is taken for gospel but it's been proven many times by developers and publishers to be pretty inaccurate. It's not like NPD.
Also I'm pretty sure last we heard the series was at 8.5m and 3.25m of those were on PC according to Steamspy. I've never heard of 9m and 5m on PC.
I think it's really misleading to put sales of the first Dark Souls on PC on the same level as the console version as it was sold from the get-go for $40 instead of $60 for consoles. After a month it was readily available for $20 or less. And a lot of those sales are from Steam deals where the game was $5. It's happened a lot lol
Trusth me, Zhuge posted a graph about Dark Souls sales before Dark Souls 3, i don't remember the link but way more than half of Dark Souls sales were on PC. We can ask to him when he see this post.
No, Bandai Namco stateed that 3.25 Millions of the "Over 8 millions" of sales of Dark Souls 1 + Dark SOuls 2 were for PC, Demon Souls + BloodBorne sales surpass 3.25 Millions, According to VGChartz Dark Souls sold less than 2 Millions in total for Xbox One, this means 3+ Millions of sales for Playstation.