Only a dummy gets involved with so-called "contractors." Hire a qualified actual worker yourself. Check out their resume/background, etc. RULE #1..NO ADVANCE DEPOSITS! Pay daily or weekly or upon satisfied completion according your standard, not workers. Contractors are merely employment agents. If that's the way you get work done, then go ahead and waste your money and wind up with the myriad of problems enumerated upon in the news clip above. RULE#2.. NO SMOKERS. They are lighting up on your money. RULE#3: No cell phones while working. Talk on their own time after work
As a painting contractor I find that most contractors charge between $20 an hour and $45 an hour plus paint and materials pending overhead here in Pennsylvania i figure $30 an hour is a safe bet. figure a good painter should be able to prep a 12 x 12 to a 12 x 15 room, caulk, apply 1 or 2 coats to the ceiling 2 coats on the walls and 1 coat on all baseboards, trim, doors and crown moulding in an 8 to 9 hour day. This is with minimal or minor spackling repairs like nail holes and nail pops, not cracks and peeling tape. Thats extra paint is usually  $30 to $70 a gallon pending quality. A room this size will need 1 gallon for the ceiling 2 for the walls and maybe 1 gallon for the trim, doors ext... the square foot price is $1.50 - $3.00 as far as asking for money up front I never ask. If the home owner buys the paint there is no need for money and if your buying the paint and your an established contractor you have an account with your supplier's.  any ways that's my input and guidelines 
If you paint over dirty, oily surfaces, the paint will easily chip or peel off. So before painting, clean grimy areas with a deglosser or heavy-duty cleaner intended for prepaint cleaning. They work well to clean painted, varnished or enameled surfaces to improve the adhesion of the new paint. They’re ideal for cleaning greasy or oily areas like kitchen and bathroom walls and removing hand marks around light switches and doorknobs.
IF the average cost is $1700 to paint an interior, then that means the cost of paint is approx. $200 (12% of the job).  Or better said 5 gallons of paint (if the average cost is $40 retail).  The average room takes 1.5 gallons which will cover 3 average rooms.  Doesn't sound to average to anyone with knowledge of this industry or a average house.  You are misleading consumers and should do a better job in your research.  No wonder so pay people think prices to get work done by professionals is high.  Its not high, its actually average which is more like $3700.

House Painter Co