yes, i should have mentioned trust earlier, as that’s even more important than information in negotiations. two parties who don’t know each other will start with relatively low trust, so highly divergent bids are a signal of that. as information is shared, and assuming trust signals trend positive, the bids converge. also, you want to know early if the other party is a sucker or unreasonable, and to weed out lemons. all that’s a direct consequence of our intuitive sense of fairness and value.
salary negotiations are a little fraught because they’re low trust and information-asymmetrical to start but because jobs are a longer term relationship, you don’t want to trigger distrust. one of the reasons employers like to keep salaries/comp private is that it gives them an significant information advantage in negotiations. they know every comp package they’re paying and that they’ve offered, as well as comp packages at various other companies and industry average info that they subscribe to. it’s often prohibitively expensive for each worker to gather similar data, which creates a real disadvantage.
in light of that, i’d suggest starting at 110% of what you’d consider a reasonable maximum, not minimum, and have 3 justifications ready (based on value you’ve generated for other companies, your overall experience level, specific skills/relationships/resources you bring to bear, public salary/comp information, etc.) to counter the obvious first objections (usually on experience or comparative comp data). anchoring high, but not unreasonably so, and then negotiating with justification should get you a higher comp package while not triggering distrust. you’ll also learn some important bits about the company which may give you reason to forego the offer (happened to me a couple times actually).
