300 I think what carter is trying to tell you is how PPG reccomends on their DCC single Stage line of paint .
If you take their clear and mix like directions and then add it to the last coat of Mixed paint , this will help on Color hold out .But their DCC is usually a high solids and coverage is excellent.

I Have done this alot with good results.
I re read your first post and if its Your car , why is a customer paying for the paint ?
And like usual you will always get what you pay for. Cheaper isnt always the best way to go .
I have never figured out why a guy would spend thousands of dollars fixing a car , and then skimp on the paint.

Remember if you mess up with single stage you will have to wait and re do the mess ups, with base clear you can let the base dry for a few minutes and sand out your BOO BOO and keep on spraying , and if you get a run in the clear keep spraying & you can sand it lightly when dry and buff it out , no re -painting.

I dont know how good you are behind a spray gun so I guess its up to you , you are the painter.
SprayTech