If I come to you, it's £35 for the first hour, per half thereafter. Parts or specifics are normally £5 each, so £35 for first hour, + £5 per brake (£45) and if it takes me 20 mins, you get included fettling for the next 40 mins.
There's neraly always something else "while you're here ......"
Some may expensive, but these are London prices for a mobile service, personal attendance and no need to get to a shop with no brakes1