Anon, don't pretend you didn't hear, express sympathy. You don't have to know a person to know grief.
(And then you become a human to them, and they'll remember you need your haircut finished. Even if they're annoyed, they can't really say so if all you've done is express sympathy. They'll cut your hair just to be rid of you.)
Try $80 or $90 these days, barber shops are the ones that start at $40 (unless you go to a great clips or something, at which point you really should just do it yourself)
Level of social interaction I'm prepared for: have a haircut without displaying any human emotions or interacting with other members of the human race.