There's another way between injected syrene (50K pieces?not much less anyway to keep back the mould costs) and cast resin (300-500 pieces?), from a couple years there are services offering low cost injected molds, done by alu insthead steel. They'll be good for 2-3K pieces only. 4-6 variants of a subject (ex. a 250GTO) for 500 pieces and I'll avoid Ferrari rights? And offer a product with half the cost of a resin kit but precision/quality/thickness of a plastic stuff?