With the current credit system, opening a business really has no benefit to the owner aside from having something to do. They gain no profit out of it. There's no money being spent or exchanged and nobody is being paid. Gathering the items to run/give out at the business is also at no cost for them, since everything is 'free' if you have the credit perks to have access to them.

Characters cannot be paid in any which way unless credits are transferred (or a person with bigger credit perks trades off something that a person who has smaller credit perks cannot obtain on their own.)