The 10-15% of retail is spot on, because the retail markup is in the 80-90% range. Whatever the retail price is, you can bet the cost of labor and materials is about 10% of that. For a time my mom worked for a clothing designer in New York (Paula Saker). Saker did designs under her own label, but a lot of what she did was exclusive stuff for stores like Bergdorf Goodman, Neiman Marcus, Barneys New York, Saks and Bloomingdales under the store brand labels. There were, for example, dresses that sold for $2000 at Barkeys New York that my mom bought for $150. She had some pantsuits and skirtsuits for work that she paid $50 for, that sold for $500-$750 in the stores.