That's their job? It's not even limited to private insurance companies. Public health systems have lists of what is considered good value for money too, even if the treatments themselves are theoretically life saving. The US is the biggest market for new and rare drugs specifically because other countries consider the prices too high.
If you think that denying a specific treatment (justified or otherwise) is comparable murder for hire, then I don't think there's anything worth discussing between the two of us.
Yeah, in my opinion an unjustified and profit motivated refusal to save a life is the same as intentionally taking that life. It's just the trolley problem and you're arguing that there is some innate nobility in refusing to touch the switch.