Its always good to go on case to case basis and lets assume 3 scenarios
1. You have too many clients to handle
2. You have too few clients to handle.
3. You have sufficient clients to give you rates you prefer.
Now in the first 2 cases you have to get a balance of price to move out some clients or add them depending on the scenario you are in and that would mean you are in point 3 like situation and I think that is the right price for your right service.