This quote below is from Seth Godin... I thought it was appropriate.
My take on pricing is that I do NOT create an hourly schedule for my consulting clients. I meet them, evaluate what is needed/asked for, and then tell that client my fee for the service. It is based on my past experience of how long it will take me to complete / how hard it is / how much hassle .... etc. It is not a formula. It is my gut instinct and that is it. I don't print a schedule in writing. If the client doesn't want to accept my fee then either we negotiate or he goes elsewhere. That would be considered "market pricing" -- If the fee is not "worth it" in the client's mind, then they won't pay. I rarely ever have anyone walk away.