I am not sure where my intrigue lies with prostitutes, but I think it is because unlike 99% of society, I admire them. As you noted, it takes bravery to stand on a street, scantily clad, availing yourself to anyone who happens along with only your wits about you to keep from getting into danger. Then there is the skill in what they do, but beyond that, after they are done they are probably better psychologists then accredited psychologists are.
I say that because I had a friend that was a prostitute and she said after they were done, it was amazing what the guys would say. I told her she needed to write a book as she was a 3rd generation prostitute and had tons of stories from her, her sister, ...... and grandmother.
I do feel saddened by those that are where they are by coercion, demand or addiction, but those that work it, and work it to their advantage, I think they are not to look down upon.