Most expensive haircut I have gotten (as a regular) was 35$ at some hair salon on Newbury St. in Boston (John Pierre).
Standard haircut I've gotten (as a regular) was 20$ at Floyd's Barbershop in Boston (Backbay)
Least expensive haircut I have gotten (as a regular) (in the past 5 years) was 12$ from a barber shop run by Vietnamese folks (down in Lorton, VA).
35$: Hair cut was always good (blending in the lines), consistent.
20$: Hair cut was almost always good (blending etc.), consistent.
12$: Hair cut is decent, blend not as good, not as consistent, but passable due to price.