I've tried a search on price, and the cheapest actual WG in Bristol - excluding masseuses etc - seems to be this one, at £30 for half an hour or £50 for an hour: bristolgirl14
However, some alarm bells are ringing. Her likes-list includes bareback (though not unprotected sex), even though her FAQ categorically says that she does NOT do bareback. She has 1 positive feedback, but her feedback is hidden. And she expects punters to send her a face pic beforehand!