As a man... I end up paying for sex almost every time. If it's not cash up front then it's something else further down the line. The woman that enjoys sex for its own sake and can have it without turning it into some kind of twisted power game or feeling that she is somehow then owed something for her time is rare and ought to be celebrated.
A few specific thoughts on the issue
Professional sex workers are just that: professional. In general (there are exceptions, both individual and general by type) professional escorts will be clean, safe, and experienced. Most of them get checked out monthly, many of them don't even have boyfriends/girlfriends or casual sex, especially if they are working for an agency/brothel/massage parlor. Most of them use condoms every time, and then wash before and after. They won't get caught up in the heat of the moment and not feel like using one, they won't forget to bring one, they won't risk having unprotected sex with someone because they tell them that they're clean. How many "normal" guys or girls can you say that about? They know what they're doing and the good ones will do what they can to make whatever time you spend with them enjoyable so they can get repeat business. Though of course sex with a prostitute is riskier than, say, sex with someone you've been in a steady monogamous relationship with for a while who you've been to the clinic with to get tested together, it's also a whole lot safer than hooking up with some random person you meet at a bar or club or online whom you know virtually nothing about. Even the monogamous relationship thing is only safe if you can trust your partner to not cheat.
Snoozan brought up the fact that women can get sex for free pretty easily, and that's also true, and probably a big part of why female prostitutes are so much more prevalent than male ones. That, and females typically feel more strongly that they shouldn't have to pay for it, because as I outlined above, most of them imagine their coochies to be not so much a source of pleasure as it is some sort of valuable commodity to use for barter or manipulation. This disparity in sexual power level between men and women (with women adopting the role of givers and men adopting the role of seekers in sex), added to the inequity of economic viability between men and women, leads to the traditional scenario of a male John and a female prostitute. That it would occur to women to even want this (good sex with no strings attached) I think is probably a good thing, but at this point the necessity for a woman to spend money in this persuit is minimal. If you're an attractive woman and you ask any available guy (and most "unavailable" ones, too) if they will have sex with you no strings attached, odds are heavily in your favor that they will say yes. A guy doing the same thing to a woman will only get ignored, slapped, or kneed in the groin.
