I am told the hobby is a business, negotiations happen all the time in business. If the provider does not want to negotiate a lower price, thats her decision. But sometimes you never know the answer to a question if you dont ask. But in any business, you should not be offended if asked to take a lower fee, just say no and then the hobbyist makes a decision about seeing a certain lady.
But I will add that is a lady has a standard fee of say $250 and a hobbyist offers $100, then thats in poor taste and he should find a different lady. Same goes for a lady, if her stated fee is say $250 and she quotes $350, then as a hobbyist I would walk away.