As you walk through your lighted rooms (preferably day light) see if the new coat has light spots showing the precious paint. This is call "bleeding through". This means that there's only one coat of paint or the paint was diluted or the trasition of colors were from light to dark (or the other way around) and primer was not use or the painter is inexperienced.
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
This was very helpful. I wonder if i would really follow through and check to see if my painter was cheating me. I used a painter I found on Angie's List. This was 5 years ago. He did a great job. I know he did patching only for about a day and a half. We decided on the kind of paint before he started. that is what he used. I don't know if I could stay on top of him and watch him open every can of paint.