Pricing Costume Jewelry Design

Hello,

I have recently been contacted by a major costume jewelry
manufacturer (that sells to Neiman Marcus, etc.) to assist in a
designer line. They have asked me to give them a quote, and I have
no idea how to price out the creation of a master ring for this kind
of production. Anyone with any experience with this sort of thing?

Thank you,
Lisa Krikawa
Krikawa Jewelry Designs