Not sure how any body else paints but the way I do it for a bio, its about 5 layers. Primer base coat, top primary color (silver, gold, metallic), weathering for detail, airbrush highlights and tints, then finally a sealer coat of clear matt or gloss spray to protect the nice paint job. materials: 3 cans of aerosol and some airbrush paints and weathering paints which I use waterproof shoepolish. So a lot of labor goes into a nice paintjob and usually the bio would show it. I usually charge $100 for all materials & labor.