Thanks man!
Yes, this looks like a time and materials situation. There are too many variables involved - condition of the cabinets, cabinet style, door style, number of doors, wood or other construction, hardware, etc., etc.
Just to get a point of reference, I’ve estimated the time to paint one 30”x30” cabinet front and with double doors, assuming the cabinet is in good condition and not very greasy/dirty.
Remove hardware and door, clean and prep: 10 minutes
Apply one coat of primer sealer Prime/seal to cabinet front and 2 door (2 sides): 15 minutes
Apply two coats of satin latex enamel to cabinet front and 2 door (2 sides): 30 minutes
Total 55 minutes (round up to 1 hour)
30”x30” cabinet = 6.25 SF
Approximate rate is 6 SF per hour
You would pick up speed as you do more cabinets. Let’s say this rate doubles on a 100 SF cabinet job. At 12 SF/HR, it would take 8.3 hours to do 100 SF. Of course, you still have to factor in setup/cleanup time, and time to reinstall the doors, and hardware.
I’ll go with time and materials, but I’ll try to time myself when I do a kitchen cabinet job and see how far off I am on my estimated labor rate.