I've never heard a good argument against prostitution. The arguments that I hear are against trafficking, rape, child molestation; which are all non-sequiturs: true and valid statements that do not support the argument itself. Can anyone here argue against prostitution per se? I'll listen.
Yours is a short question to make, but it requires a very long answer, not fit for a comment box. The negative consequences of prostitution are deeply personal because the effects of sex on the participants go deeper and last longer than the effects of the act of copulation. If you want a good argument against prostitution one route could be to understand the link between sexual expression and: intimacy, self esteem,…
I've been a customer of several sex workers in many countries and most of them are actually OK with their job and lifestyle (I've asked several). In many places it's the best/only opportunity they have to earn good money and be independent. They find it better to sell their bodies for 1 hour tops with rules and regulations to several men than to have to marry and stay with one man that hits them and makes their life miserable
Another thing I've found by experience is that most women see prostitution as a temporal thing to make some money and then quit. I'd love to see research on the topic but from my experience it's a job that they do for months, maybe 1 year at maximum, but do enough money to quit and do something else.
I think overall legal prostitution is way better than black market prostitution. No-prostitution just won't ever happen no matter what, isn't it the oldest of jobs?