There is a curious form of homeostatis in consulting, where both "too many clients" and "I'm too tired" are signs that you are not charging enough money. You should charge more until they cease being problems.

The scary part about this advice is how freaking hard it is to actually chase away clients by raising prices, if you have a habit of delivering.

Rand Fishkin, whose SEO consultancy used to get up to $1k per hour (and was almost certainly underpriced given the class of client they worked for by the end), has a very instructive comment on the post about how they kept walking up rates without chasing anyone away. Basically, there is an unknown "true cost figure" in the client's mind which includes both your bill rate and risk of the project going totally haywire. As you lower the client's perception of risk, you can capture more of the "true cost" before getting "ugh, too high" feelings from the client.