When it comes to painting there really is no standard pricing. Each painting contractor prices according to their own method - sometimes informed by experience and knowledge, and sometimes not. You will undoubtedly see a wide range between estimates.
The first thing you can do is figure out the cost of the paint. A typical room (12' x 14') will use 2-3 gallons of paint for the walls and ceiling. Add a gallon if it needs primer. This means the paint for your room will cost between $80 and $200 depending on the paint you want to use (top quality paints will range between $40 and $60 per gallon.
The labor rates will vary widely around the country, but typically painting contractors will charge by the day - $200 to $400 per day is common in the Northeast. A typical room will probably take 2 days. One day for setup, preparation and priming. And then the second day for two coats of paint and clean up. So that means painting a typical room will cost between $500 and $1,000. Remember, this is just a really rough example to give you an idea. Each painting job is different, and the prices you receive for yours may be very different.
That said,
If you are thinking of hiring a painter, there at least a few things to keep in mind when doing so. Many people don't understand the difference between a good paint job and a not-so-good paint job, and you don't want to learn the hard way. Here are a few tips to keep in mind when choosing a painter: