Lots of driving instructors charge a 'car hire' fee to use their car on the day of your test. This can be well over £100, and that's on top of any lesson fee before the test! Many just charge a lot because - they can get away with it!
I don't do this. My charge is based on the time taken, and nothing else. To allow time to drive to the test centre and have a short warm-up drive means that the 'lesson' usually starts an hour or so before the test start time. By the time the test is over, and we've taken a 'pass piccy', that's at about the 2 hour mark. Then it's just the drive home, let's call that half an hour. In fact, it usually ends up being longer.
So, that's 2.5 hours, and based on my normal 2 hour rate, the test day fee is just:
If additional warm up time is needed, then it's normal to go for 3 hours, where the usual rate would apply (so that's £123).