For those who have occasion to price their woodworking projects, there is an EXCELLENT, _very in-depth_, article on estimating/pricing furniture projects in the December 2006 of "Woodwork" magazine.
Well worth many times the US$4.99 price of the mag.
If you do any commission work you owe it to yourself to seek out and buy a copy at the earliest opportunity. You will not regret it, guaranteed.