The rough "rule of thumb" for the ratio between manufacturing costs vs. retail price usually falls in the 1:5 or 1:6 range. This, however, is normally based on manufacturing enough of the product to reach so-called "economies of scale". This, however, does not always apply to low volume speciality products, such as high-end audio gear. The manufacturing cost to retail price ratio for these sort of "luxury" goods may be in the 1:10 to 1:15 range. And then there are the markup ratios that make no rational sense at all, such as diamonds and high-end audio cables....