I have a cousin who spent several months working temporarily in Manhattan in 1994, and I remember thst she was paying $100 for each colonic. She was getting a daily per-diem allowance in addition to her regular salary so she was able to afford it, but I was blown away by how much they cost at that time.
That was when I was just getting started in the colon hydrotherapy field, and $60 - $65 was considered expensive back then. She really liked her therapist and said everything was first class, and I'll get the name and office address from her in hopes her therapist is still practicing there. It was on the upper west side opposite Central Park.
I wouldn't even want to guess at the cost today if it was $100 12 years ago!