Comment Pay for Service Provided (Score 2, Interesting) 458
If you charge by the hour, you are committing to a larger workload. Create a specific list of deliverables (small, workable code chunks) and price each one according to about 150% of the number of hours you anticipate times the going rate of $50 to $75 an hour. This gives your client a fixed cost (which they should appreciate) and you the flexability to work at your pace. You'll have some evenings you'll bust out a massive section and others that are slower but it won't matter if it is a fixed cost.
I released three titles under this model and it halted many arguments. One warning... set your timetable within easily reachable goals. Your client will expect a finished (and working) product exactly on the day you promise it.
Good luck and welcome to the evil corporate world!
AG