The price of power is letting the hag live. I don't think that should change.
Agree. I also agree with Crimsonrider that the story should make this make sense, and that simply not having the option to *try* to kill Ethel as it stands doesn’t ring entirely true and given this whole quest line is generally so great, it seems worth Larian putting a bit more effort into the end to make it wholly convincing.
I personally don’t see Fezzerk as a direct equivalent. I can’t recall what he gives you as loot - a heavy axe? - but I don’t think it’s nearly as valuable. And the whole quest line with him isn’t about deals and bargains. Plus, unlike Ethel, I’d struggle to think of a way he could realistically escape death at that point.