I guess it's about value for money and your own personal preference and how much business you get for the prices you charge. My rates in accordance to what I offer and what I feel comfortable with always ensures I am almost always busy. Me personally I'd rather charge 100 for an hour offering lots of different services that I am comfortable with doing and get three or four of these bookings a day rather than charge 1000 for an hour and never get any work ever again.
I am the same, I have had normal jobs, so I value the money I charge even though its classed as low to some service providers, I didn't go to uni to learn what I do, so I am grateful for what I earn and very comfortable with my services, which makes sure clients come back.