you'd be better off quoting per job , going by the hourly rate will probably work out to your disadvantage , most decent programmers will know roughly how long a job will take and they will base the cost on that , if they run into problems due to a multitude of reasons they will have to eat that cost and not you , its more stability that way for you , you can base your quotes upon actual costs rather than finding out you chose the wrong programmer and they ate up all of your profit because of their incompetence or what have you
ive got a day job and am not interestest in programming but i figured i'd toss out some food for thought
A poet knows no boundary yet he is bound to the boundaries of ones own mind !! ........