Chemistry is definitely cheaper to study at a University if you want the lab experience, which I find very important. (Imagine learning how to code in C without a compiler...)

Between chemicals, ventilation hoods, labware, and instruments, you'd probably spend a few million trying to teach yourself chemistry at home.

Khan Academy is great, but not what I was asking.

It's a pretty good attempt at what you're asking (it's college level chemistry with fantastic instructors, for free, online)

CS is pretty unique in the realm of things that typically require a 4 year degree to work in that are accomplishable without. The required capital is sitting on most desks in the country. Chloroform less so

I imagine it would be almost entirely impossible to work in bioscience without a relevant degree.

I mean, I'm not really looking to work in the biosciences. I have a PhD in computer engineering and am happy with my job. I'm looking to take classes past the organic chemistry classes I took in college.

The Chemistry subreddit has a list of recommended books.

You can just look up some undergraduate chemistry course listings and follow the prerequisites to construct an order in which to work through them.