I am currently in the higher range, after five years previous exprience, which is $15/hr. Some salaries vary in our state by location, i.e., urban vs. rural. I am in between both. The advocates in New York City, for example, are salaried at much higher rates.
Higher education often does not address individual skills necessary for advocacy, unless you are specializing, i.e., legal, medical, etc. Often times, it is experiencially necessary to have been in contact with victims in a variety if settings in order to advance within a particular organization. Administrative positions often require masters degrees.