You can define custom rates for each service the staff member will be paid in the Staff Profile page. This rate will override the default pay out rate defined for the Service.
Navigate to Staff > Staff profile > Payout Rate
To access the pay out rate, go to the Staff Profile page and select the Payout Rate tab. Over here you can define the custom pay out rate. You can either set a fixed amount to be paid or a percentage amount to be paid. If you select the amount type to be percentage than when the price of the service changes the payout rate for the staff member will also change.