I consider it rude and I don't except lower fees. Unless it's a deal struck with a very close regular.
My reasons are: I do very well with my rates, so don't need to go lower. British culture is not really haggle friendly. You don't haggle with your dentist or cinema. There are plenty of girls who offer their services at all sorts of prices, so find your match.
Don't wish to be snobby but I offer what's advertised at the price stated.