To take a silly but illustrative example: if I'm looking for a javascript developer, I don't care if the person I'm interviewing also has a law degree from a top tier school and can craft airtight patent applications even if I may have some use for that skill. I am hiring for a javascript developer. That is the role I need filled. I will offer a salary range based on that need.
It is a silly example but I see the issue so often: someone will apply for a role and then expect to be compensated for their other skills. While, sometimes, it may be worth it to do a bit of management gymnastics and get someone brilliant through the door and find out how to fully leverage their talents later, most of the time that's just wishful thinking on everyone's part.
How often does your eventual accepted offer land at the high end of your offered range? How often at the low end?
I ask, because it often seems unproductive to negotiate within-range on merits. If you're willing to pay up to X, I as a candidate am going to expect that amount. Anything less is letting you, the employer, capture the surplus...