I've seen two competing philosophies of how to determine pay.
First, you can find a large pool of candidates, learn the typical wages in your market, and make offers pegged to the average (with some offset). You will learn what fraction of your offers are likely to be accepted (maybe shoot for 60%), and adjust accordingly. This works if you want to hire a dozen or more people over the course of some months.
Alternatively, ignore price, look for candidates, and when you find the right one, open a negotiation where you determine what price they are willing to take. If you need to hire a small number of specialists, this may be the best way.
I have also experienced failed recruitment schemes, such as ignoring price until the end but then pitching a "fixed budget" (which sometimes means "political limitations").
You can choose which method to use every time you hire. Great candidates may also be choosing, and you know which model they will cater to.