The cheapest hair cut I have got is in Guangzhou China. When I went in to the shop a lady asked me which kind of shampoo I want. I asked what's the difference she said if I pick Vidal Sassoon it will be more expensive. I asked how much more expensive and she said 15 yuen. I though it costs 15 yuen more to use Vidal Sassoon versus some unknown brand but later found out that it was 15 yuen total for using Vidal Sasoon and 11 yuen for using unknown brand.
So I went for the "premium" package for 15 yuen. One lady shampooed and scrubbed my scalp for full 20 minutes, then washed my hair, then massaged my neck and shoulders for 10 minutes, before I was sent to the shifu to get my hair cut.
All for <SG$4.
In US my wife cuts my hair most of the time, but if I go to a barber it will cost US$15 before tips for haircut only.
As an after thought the Vidal Sasoon could have been the same no-brand shampoo in a Vidal Sasoon container....I don't know the smell anyway...