Barbers strike me as a practical lot. Which makes this pricing structure seem especially strange to me.
I mean, isn’t a kid going to have less overall hair than an adult? I understand that an adult head may have less coverage percentage-wise, but the larger head-radius more than makes up for the lower proportion of hair. I’ve got to believe that the price-per-hair is considerably higher for a child than an adult under this pricing system.
Of course, I would not be so naive as to expect understandable pricing structures from hair stylists.