Mechanical Engineer III (taken from Salary.com... I know, it's not perfect, but its a quick resource for a comparison).
Designs, develops, and tests all aspects of mechanical components, equipment, and machinery. Applies knowledge of engineering principles to design products such as engines, instruments, controls, robots, machines, etc. May be involved in fabrication, operation, application, installation, and/or repair of mechanical products. Requires a bachelor's degree in engineering and 4-6 years of experience in the field or in a related area. Familiar with a variety of the field's concepts, practices, and procedures. Relies on experience and judgment to plan and accomplish goals. Performs a variety of complicated tasks. May report to an executive or a manager. A wide degree of creativity and latitude is expected.
Salary from San Francisco, CA
Salary from Iowa City, IA
Salary from Miami, FL
Compared to Consumer Price Index:
About the ratings here: http://www.numbeo.com/cost-of-living/cpi_explained.jsp
These are all relative to New York (value of 100 on all categories)