Pure Capitalism/Pure Communism more or less doesn't exist. I don't even think you can accurately make a list of 'here is how this society would run' because I think it flat out wouldn't.
Pure Communism would be a society that has no money amongst other things (And I think even North Korea has money [Not that I consider North Korea anything but a dictator state])
Pure Capitalism assumes I'm paying subscriptions to people to keep my roads paved (Which sounds like government with extra steps) and a variety of other things that just outright doesn't exist.
If you want to read more about the complaints about Capitalism, you see more of it in his discussion about worker alienation. I forget which text this is in, I read Marx when I was in college out of my textbooks mostly so the names of his papers escape me, but there may have been some of it in the Manifesto.
Also keep in mind: This isn't 'modern day' Capitalism. This isn't 'I work 40 hours a week and make minimum wage' Capitalism, this is 'I work an absurd amount per day, per week, for peanuts'. This is 'Children in the factories' 'Striking gets you beaten/killed/replaced with scabs', 'No I don't care you lost your finger in the meat package keep working!' type shit.
I forget Marx's background, though I did a quick google search to get a bit more info. He was born into a Jewish family but his father converted because he couldn't be a lawyer and be jewish where they lived (The past is fun ain't it), he lived a semi-aristocratic lifestyle (Married a petty noble lady, but he wasn't a Yuppie)
His father died, which cut a lot of his income off, and he seemed to mostly spend his time writing (I think he was a co-writer for a paper)
I think a small detail I remember was: He had to write the Communist Manifesto to help pay his bills, which I thought was a bit ironic.
There's a decent amount to critique about Marx but I think he was a pretty good writer, and had some ideas that are still relevant today.
I fucking forget what it was called and it's eating at me that I can't remember, but more or less there was an idea that the lower class would rise up and murder everyone. There was something he mentioned as being 'the reason they don't do this', more or less related to being blinded by the upper classes. Also equates well to modern luxuries (Why revolutionize when I have a kick ass Iphone and computer?)
I believe he also does that thing most philosophical/sociological writers do where they go 'Here's how society worked in the past!' and then promptly butcher how society worked in the past. He wasn't a historian, a lot of writers aren't, so this tends to happen a lot.
