Okay, let’s calculate this. Gail has 40 years of experience, which is a significant amount. Her skills include Lean Manufacturing, Six Sigma, and product development, which are in demand. However, her role is in purchasing and supply chain management, which might be less lucrative than other roles. Location is St Louis, Missouri, which is not a hub for high-paying industries. Considering her experience, skills, and location, I estimate her hourly rate to be around $125. This is slightly lower than the average salary for purchasing managers in the US, which ranges from $80,000 to $120,000 per year. However, her experience and skills in manufacturing and supply chain management justify this rate.