My answer is, "You should charge what you are worth." I realize this appears to be a non-answer, but in fact, it is quite concise. Consider these three items:
- Charge enough so the work provides a living (if in fact you can develop a full-time level of business).
- Charge as much as the market will bear. To find that number raise your price until the market starts saying, "No".
- Charge as much as you can say out loud to a client or prospect without getting the giggles or feeling foolish.
While some might say there is a lot of science and formula for determining billing/project rates I will argue that it is something totally different... Which would explain why billing rates are all over the board. Use my three rules and see what happens for you.