Can't help you in your particular field, I can only back up what snailwagon said...
My company, "Field Service Technicians" make 40-50K per year. "Field Service Engineers" are pulling $60-100 depending on experience.
THe difference between the two? It sure as hell isn't skill, cause an experienced millwright with 20+ years experience has forgotten more about these machines than a kid fresh out of engineering school knows... It's the degree, that's all.
We supply machinery for the manufacture of pulp, paper, rubber, minerals, petrochemical, mining equipment as well as marine diesels and other heavy marine equipment. We also make specialty DCS and process control equipment, and Porsche Boxsters.