Let's look at this at a purely economical view...
Typical Date:
Transportation: $10 (depending on where you live, if you are picking her up or not)
Movie: $25
Dinner: Anywhere from $40 (cheap) to $120 (with drinks at a nice restaurant)
(Chances of getting laid? Let's say 50/50)
Escort: $250 for an hour (which no guy needs for sex)
(Chances of getting laid 100%)
So let's say... $80 for dinner, $25 for the movie, $10 in transportation. That's half of what you would pay for an escort for an hour. Plus, there isn't a chance that you won't get laid after you drop all that money.
I don't say hire escorts all the time, but if you are horny and just want to get laid? What's the big deal? Use condoms and get tested afterwards.
I've always found that I do better on dates when I'm not desperate to get laid. Girls can smell that on you. It's like a really stinky cologne.
I agree with what greywolf says, as long as she is doing it under her own free will, why the hell not.
*****
I knew a call girl once. She was one of my best friends and only did it when she needed quick cash. She was $200 bucks a pop and usually had someone wait in the car for her while she was on call. She didn't see it as a huge deal and never really let it bother her. She just saw it as offering another service (She cleaned houses and worked part time as CNA). Some hookers are like Xman said and some... arn't. I guess it depends on the person.
I went a LONG time without sex because of some fucked up head issues keeping me from hitting on girls. When I did, it wasn't pretty. Would I have hired a hooker just to get over that "I haven't fucked in a long time" spurt? Yes, but I didn't know how. Sex is what you make of it, if it's a HUGE DEAL in your mind, then you will have the problems that come about with it. If you don't... then you end up getting laid a lot.