How much do drama therapists make?

As with most jobs, it depends on your past experience and the facility and/or population. One objective way to find out average salaries in a field is to check out the following websites:
http://stats.bls.gov/oco/ or http://www.acinet.org. Investigate the stats for counselors, psychologists, recreational therapists, social workers, rehabilitation therapists, psych rehab therapists, etc.