If there was one book I could read to understand this company's business model and future, what would it be?

  I don't just care about engineering, I want to understand the product and business I'd be working on/for on a deeper and broader level.

I like everything about this and everything you're saying fully resonates with me. At the end of the day companies themselves need some sort of pressure on them to at least raise what's currently the "minimum." I know it's not the recruiters fault generally, and definitely a large part of it is the company itself and the incentives they setup that make it cutthroat.

On the line about the book, I would also read it. It's good for me, it's good for them.