When I was studying in England, I remember getting a haircut for 6 GBP. That was in 2008.
I don't think so. I had a haircut in Thailand by a mobile hairdresser (just a chair for the customer to sit on, a mirror that is hung on a tree, and a bag with his tools, for 50 THB. That was 2013.
That's 3 USD. Way off my target! Mental note: if/when going to China from Thailand for a longer time, get a haircut in Thailand before.