Often, the way it is portrayed in porn films it can be really erotic and a turn on, other times it's like just another hole. Suppose it depends on the director and actors.
Personally, I've had bum sex (thank you Keith Lemon) with about 15 WGs in 10 years. Some I've enjoyed, some not so, but if it's offered I will go for it. Never had a refusal, but did have one failure, as the Indian girl was very tight, and as it was second pop, a degree of flaccidity on my part, and the lube didnt help. Still I had her next meet and the one after and it was good. One of my most recent punts, in Nottingham btw, had round 2 with anal, and after I came, she did ass to mouth even with a condom. What a surprise.
I tend to select girls on reliability and service, so 'A' is not a dealbreaker, but if she will, fine. What I seldom do, is pay extra. I always expect anal in the price, and to pay, the girl has to be exceptionally special, and not ask stupid amounts. £25 is OK, but £100 is taking the piss.