I had my brows threaded on a Friday after work, and just turned up without an appointment. The woman did a fantastic job and shaped them beautifully, and was really quick and efficient. I always find threading a bit weird since someone is standing over you with their face so close to yours! But the whole experience was as pleasant as eyebrow threading can be, and I will definitely be going back.
I can't remember exactly how much it was but I do remember that I was really surprised at how cheap it was.