What to charge for decorative painting?

I have done some decorative painting in my home and some of my friends, but have never charged them. I have now been asked to paint a commercial location and they will pay me. I am not sure what to charge. The space is approximately 350 square feet, but includes several small locations, i.e. over doors and windows, etc. The process will be a 2 or 3 color "mottling" and I anticipate at least 60 hours for the project. I am not a professional, but she likes my work. I do not want to over charge her, but at the same time, do not want to sell myself short. Any advise?

We had a decorative painter redo our kitchen cabinets. It cost about $3500. We are getting ready to have our living room and entry way repainted in one color. It is a space of about 1600 square feet of painted surface. We have a quote from a very good painter to do the work for $1000 plus materials. I'm guessing he will take about two days to do the prep and painting.

If you think it will take 60 hours, then it will probably be more like 80 hours. At $35 an hour, that would be somewhere between $2100 and $2800.

You might consider offering to do the job for something like $4000 with the understanding that you will reduce the price for every hour under 80 that it takes at a rate of $25.

One final idea. Have you simply asked some local painters what they charge per hour? I have guess $35 but it could easily be $50.

Oil Field Trash has a good idea. How about this: Tell her you'd charge $2500. Then tell her if she'll put a small TASTEFUL plaque near it with your name and phone, you'll do it for $1500.

Or, another way is to charge her full price, and then you'll pay her $50 for every referral that hires you.