We charge $1 per square foot of wall and ceiling, per coat. We charge $1 per linear foot of trim (baseboard and door and window trim) per coat. Most wall color changes require 2 coats and trim needs two coats when changing color. Large cathedral ceilings and stairwells may require extra surcharge.
We recommend Sherwin Williams product but are happy to use your preferred brand. In Sherwin Williams interior paints there are the following sheens:
Gloss (some product restrictions)
Semi-Gloss (almost always used for trim and bathrooms for washability)
Satin (like egg-shell in other brands, most common sheen for walls)
Flat (commonly used for ceilings, not good for any surface that will be touched)