Most of the exposure I've had to addiction psychs have worked in inpatient hospital settings. I know OldPsychDoc tends to work with a lot of addiction patients. Maybe he can provide more insight.
I know that the addiction floors I've been on have salaried psychiatrists, who presumably make the going rate for psychiatrists at their experience level.
Personally, there isn't enough money on this earth for me to specialize in addiction psych, but I know residents that have mentor addiction psych colleagues that apparently make tons of money with private addiction clinics, and even running methadone clinics (which are apparently also quite lucrative).