how much profit the companies running these businesses are making?

Well, the article mentions $6.2 billion being shipped overseas, so they're making at least $1.5b, which is nothing to sniff at. But I imagine most of it is used domestically, and considering the massively inflated hospital prices here, they probably make at least as much as from the exports, so you probably get less than 1/3 of what it's value is, at the very least 2/3 if you assume they make nothing from US plasma (lol, lmao).