The old rule from the Army - Depends on the terrain and the circumstances.
If you reside in some places on the globe then you will have to charge low rates as that is what the local market can bear. In other places the rates seem astronomical, but the costs there are much higher. Rates here in South Texas are rather low, but there is little demand. In Southern California the costs are much higher so the rates are much higher. You also have to look at whether you are clearing any money at the end of these jobs. Enough to cover costs? or are you really doing it as a hobby?