Well, I have seen men (not 'gentlemen' obviously) who have similar thoughts to you Mr McTojo. It's rather sickening to see them drooling at the mouth over teenagers and young women, knowing that they can F%&k them for a 'good' price.
Rather often its not even that these women WANT to sell their bodies. Generally the cheapest women have no choice, they are being forced into it at a young age, then have a huge debt hanging over their heads, and they have to service sicko's with ridiculously cheap sex, which is nothing compared to what they have to pay in overheads.

I should hope that if you were wanting to go and have cheap sex that you could at least give them a rather hefty tip, perhaps a nice dinner out, a new dress, and maybe you could buy her a new place to live? So she doesnt have to be reminded of the men she sleeps with 24/7 because she has nowhere else to go.

Sure in some countries it's a different story, and the women want to get paid to have sex, some may even enjoy it, but when it's as 'cheap as chips' generally its not what they really wanted out of their life.

Anyway if you really want to go to China and pay 50 yuan, have the decency to treat her better than others probably have.