While a 1/200 scale model may be dimensionally 1.75 times the size of a 1/350 scale model, the surface area is actually a function of the square of the increase. Imagine a cube whose edges are 1”. Each side has an area of 1 square inch, and there are six sides, so the total surface area of the cube is 6 square inches. Now if I double the length of each edge, I now have a cube with sides of 4 square inches for a total of 24 square inches. So to paint the larger cube takes 4 times (2 squared) the paint just for one coat. In the case of your model, you will need 1.75 squared (= 3.0625) times the amount of paint you would normally use for one coat in 1/350 scale to do the same job in 1/200 scale, assuming you are building a model of the same ship in both scales. Isn’t math fun? There will be a quiz tomorrow. Bring a #2 pencil and a Big Chief tablet to class. 
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