Resources for Pricing?

Have been doing commercial art for longer than I’ll admit. The “Graphic Artist Guild” publishes the “Pricing and Ethical Guidelines” book which is a superb reference, especially if you freelance and don’t deal directly in some of the more unique areas on a daily basis. If a client comes up with something “different”, you can at least get into the ballpark using this book as a reference.

Does anything like this exist for Industrial design?

Are getting more involved with dimensional design. A current client in the Point-of-Purchase arena is interested in hiring me for concept work. I will basically provide three views (to scale), engineered to mate with current machines/components. No modeling required, but the concept art/graphics will be detailed enough to turn over for production. Some of the designs will more than likely be patentable.

What is a per hour price range for this sort of design work?

Thanks in advance.