How much a have to charge for exterior job paint in concrete?

Since you are asking we will assume that you are not a professional painter, right? To start with you will need to tell us more about the texture of the concrete and what primer the owner wants as well as top coat.

ballengerb1 is right. We will also need to know what equipment you have-sprayer/rollers.

Jason, most of us will normally tell you to get 3 bids from pros, average the bids and then cut at least 40% since you aren't a pro.