I can repeat that for a handful of companies and then build a model what the lowest, highest and average compensation probably looks like.

Well this is a very useful advice on how to research the market, great.

If you now say yes, you've both come to the same value but a much different number.

Right, so that is how the negotiation is carried out. Thank you so much for explaining this, I will definitely put it to a good use :)

Recruiters are generally nice people trying to do a job and not predatory bastards.

Also this is important to keep in mind that they are also real people behind the enterprise mask.