In Philadelphia it's worth $50 bucks
I suggest allowing your clients to choose between the various payscales mentioned in the previous post, at least initially. People who are well-rehearsed and don't need a lot of production will appreciate hourly rates; others may require more time and would prefer to pay by the song or project.
Superficially this may end up saving your clients money (which naturally means less money that you'll receive), but recognize that you don't have to charge everyone the same rate. If one of your prospective clients has ill-prepared, sloppy work that's going to require a lot of time and effort to produce, and they want to pay by the project because they know how many hours are necessary to get what they want, just give them a higher project rate.
Size your clients up; you can feel comfortable asking them about the details of their project. How prepared are they? How many songs are they going to record? Do they want a lot of effects? How many people are in the band? Once you know what you're getting into and the client has chosen a payscale that suits them, give them an estimate of what the entire project will cost. Remind them that it's only an estimate, but naturally try not to let the final cost exceed your estimate by too much.
Can't think of anything else at the moment. Hope that helps.
Peter