Of course, others have their opinion, but in one college class I took, a few years ago, about half of the girls that were supporting themselves through college (as opposed to the ones whose husband or folks paid for tuition and housing).I think that it is dangerous to assume that a call girl, escort or masseuse is intrinsically different than any other woman. And as you grow more experienced in the world you will see that there are many other women out there, that would qualify as a "working girl", if you go by definition.
Besides, you are hinting that working girls are less worthy of consideration, which probably would backfire on you eventually anyway. Why buy into a stereotype that they have about you? And you are a john, you are here.
My realtor told me a story, about a good looking lady in her office, who only dated rich guys.
Is that a working girl? Or is that a working girl whose entry level price is higher than what you can afford? She will leave if you don't buy her a new jag every two years, and first class trips to Hawaii. Yes, money comes into play.
I think you should marry your high school sweetheart if you want someone without a past.
At the end, every woman is a whore and every man a john, just ask a divorce lawyer. The difference is that some get it before marriage, and some afterwards.
Perhaps the way to see if a woman is a working girl is to see if she holds title jointly or as a single woman.