I as the client would want to know that before you are even considered. There are many housewives who will do it for less. Figure out time you think it will take you and the amount of paint unless the client is buying. It is a guess on your work speed...and the quality of your workmanship. If you want to do more painting, you got to have reasonable rates and do a good job...as most of the jobs you will get will be by referral from a satisfied customer. Gaffed customers tend to not say good things about you.
I think painters charge by the square foot of floor space. I would talk to some painters to get the going rates. Try linkedin to find some. I would also calculate all your materials costs, and then how long it will take. Add overhead and profit into the job. Remember these jobs often take longer than expected. how many quotes are they getting?
