Interior Paint estimate

I know there are a few painters on here so thought I would ask. I normally do all my own work, but I just don't have the time lately so am thinking of having somebody paint some interior walls for me.

I have no idea what it costs and I don't want to waste people's time if I can't afford it. I know nobody can give an exact number without seeing it in person, but what would a BALLPARK price or price range be for painting something like a 20x20 family room with 3 walls? There is currently a dark olive color on the walls and we want to go lighter. What are we talking...$100? $200? $500? $1000?

I'm a picky SOB so would expect sharp lines, clean workspace, quality paint, even coats, etc. If I am going to hire a professional, it should have professional results.

PM me if you are interested or do not want to post any numbers to the public.

Thanks.