Garment production is an area that benefits greatly from economies of scale. If someone could sell as many kilts (or kilt-like garments) as Levi Strauss sells jeans, there's no reason they couldn't make them sized in the four dimensions that matter (waist, hip, waist-hip distance, and length), and at a reasonable price. It's simply a matter of deciding to spend the money to make the patterns, and the machinery to make it practical.