I don't do SEO jobs, but i've friends who works with SEO. According to those, salary for SEO job may be approximately as follows:
SEO Analyst: $40,000
SEO Specialist: $45,000
Search Engine Optimization specialist: $75,000
SEO Manager: $77,000
SEO Sales Rep: $230,000
This is what I've been led to believe are average salaries for these particular job descriptions, hope that helps.