We do a lot of boat work, since we are on a big lake. Printed graphics like that are impossible to match perfectly. However they are easy to mirror once you have drawn something. Therefore, we always quote jobs like that as doing both sides. I also tell customers that it will not match the factory graphic unless it's just solid color vinyl cut into shapes, and even then the color won't match because of sun fade.
When making the quote, you have to factor in going to the boat to photograph and measure the graphic for yourself. The marina never photographs the boat from a 90 degree angle to the side of the boat, and their idea of measuring is to have someone holding a tape measure in the photo. Sometimes the only way you can accurately replicate the shape is by making a paper tracing of the graphic because it's mounted on a curved surface. All of that is time consuming.
Then you have to add in the time to size the image in the computer, draw the shape and try to figure out what arcane combination of effects were used in Photoshop to create the printed fill, realizing that usually these are not printed digitally and they therefore can do things like screenprint metallic colors across part of the graphic, which you cannot do.
After that you figure up the cost of producing the graphic, taking into account that you often will have to do long cuts of your printed image and have tracking errors which require a reprint/laminate/cut.
And then you have to figure travel time to the boatyard and installation outdoors in the wind and sudden rain showers, or indoor installation in their cramped shop, or in their detailing bay with a crew right next to you power washing a boat, making the dirty concrete floor soaking wet. Or the customer who wants you to install the 20' long graphic with the boat on a lift in the water and a dock pole every 8 feet in the way, and the bow of the boat arcing away from the sides of the slip.
You would be surprised how much the factory graphic costs from the factory. The ones for wakeboard boats, which aren't as big as the ones on performance boats, are often well over a thousand dollars just for the graphic. But when you try to reproduce one, you will understand why they cost so much. And when you try to install one, you will see why the marina wants to hire you to screw up their $1200 graphic (and you have to replace it on your dime if you do screw it up).
After you make a proper quote, you will separate the people who really want their boat fixed from the chaff. Remember how much auto body people charge for restoration.