In UC, under Kingdom Building rules, it's convenient to fill all the Leadership Roles for your kingdom or settlement. However, I think some of them could be paid NPCs. Where can be found the costs for such NPCs, if any?
I'd use created NPCs that are selected and played (with their own motivations) instead of simple hirelings. But...
I'd look at page 88 in Ultimate Campaign. Managers are 3rd level hirelings that run a business. You can get an idea there of how much a 3rd level would cost per day (between 2 and 5 gp/day).
You also might be better off taking the leadership feat and selecting your cohort as the leader. Since you don't have to pay the cohort or the minions...
OK, thank you Bradley!