Ed discusses how to estimate future costs by listing your assumptions.
Most clients don't complain about hourly rates; they complain about the totality of their legal costs. In order to control legal costs, one help is budgets.
How to estimate future costs: List your assumptions and make sure the client understands these and also provide for change-orders if any of these assumptions prove to be erroneous. That's how you keep the costs down and that's how you keep the client satisfied.