This sounds more like hucksters pretending to be Marxists and trying to oversell books. I’m really not a fan of books that are available for free on the internet being sold way too high. If they are translations, no problem. But offering “What is to be done” for 30€, as an example, would be absolutely usurious.
I agree. I also observed that liberals will cite anything and everything to make their anti-communism valid. Starting with low level bullshit like, that Marx said he is not a marxist (Marxism debunked, you see), Luxemburg saying she doesnt like how the october revolution happened (Lenin debunked!), Trotsky disagreeing with the Soviet Union the way it wents (Soviet Union debunked) and so on. Also dont forget: Debunking Trotsky because of Kronstadt and Luxemburg is bad, because Thälmann wrote so. Sino-Soviet Split: China and Soviet Union debunked again.
Looking into the history of marxism, it is quite easy to find a ton of writings, letters and discussions. But, as an example, looking into the collected works of Lenin and making notes where Lenin disagreed with someone, is not how history as a science works. Taking Luxemburg and Lenin: She had critique, yes, but she supported the october revolution and wrote important books for marxist movement. But the most time you’ll hear how they cherrypick something and ignore the rest.