OK, as someone who does this for a living; I'll chime in on this. A lot stuff goes in to the final cost, such as any body work needed, stone chips and need to be filler, jambs, and refiting any panels. Then there is the detailing at the end.
It all depends onthe color you pic, how much work is needed to prep for paint, and how many hours flat rate is to paint your car.
2-3K minus jambs/ w minor scratches and dents. 4-5 with jambs.
P.S. If you have a scratch and u can feel it with your fingernail, it has to be repainted inorded for it to not show up on the next paint job. Stone chips also have to be filled, or they too will show up and look crappy.