[hayst4ck]

Are you for real?

You think you are in a zero sum relationship with your co-workers, but not your boss/company?

The word negotiation indicates two parties with conflicting interests reaching an agreement. You don't negotiate with your co-worker, you negotiate with an HR department. You are literally in conflict with your employer. Your employer benefits by paying you the minimum possible, and you benefit by being paid the maximum possible.

You and your co-worker benefit by breaking open the companies books and knowing how much they could be paying you but aren't.