The only place you can bribe them is their bases, and docking with their bases without getting destroyed while hostile to them is close to impossible.However, it seems that killing Nomads affects your reputation with them at the same rate as killing Corsairs, Lane Hackers, Liberty Rogues, Outcasts, Unioners, and Xenos. You can try farming some corsairs without worrying about dropping your Outcast and Rogues rep.