It really depends on the job, the industry, and the size of the company. (I was an HR manager some years back.) I worked at a geotechnical engineering company. While the engineers might be able to negotiate salaries, the support staff usually could not. If the position is easy to fill, there’s not much leeway. If it isn’t, there is. My company was desperate for a soil technician. They bought a guy a truck as a hiring bonus. They never did it any other time. That time, they needed an experienced tech immediately and were willing to do whatever it took to hire him.