Decriminalization of prostitution just means that it'd no longer be illegal to SELL sex but it could still be illegal to BUY sex. So essentially you'd be recognizing that the prostitute is only resorting to this activity as a job of last resort and the best chance to get the "supply" side of prostitution under control is to offer the sex worker any drug/alcohol treatment, therapy, and education or training for other jobs. Decriminalization of only the SELLING would leave the door open to still approach the BUYING as a crime so you can attack the demand side. If you were to just legalize prostitution it would effectively rule out the ability to attack the demand side as well as create a secondary new "black market" for non-legal prostitutes. The secondary black market would exist because their will inevitably be women that are excluded from legal prostitution for reasons such as being too young, being unable to pass std/health check ups etc. Another byproduct when prostitution has been legalized is it routinely causes the average income of the sex worker to decrease; though it's worth noting that these savings are not guaranteed to be passed onto the sex buyer. For example, just outside of Las Vegas in Nevada there are a couple counties that have legalized prostitution and the cost of an hour is often over $1,000 US but the sex worker only ends up with about $300 after everyone gets their share.
My experiences may be fairly unusual in their variances but I have worked as a streetwalker, in a brothel, for an agency, and as an independent call girl. I'm not sure if I'd really qualify for the super high class escorts division if you are just going by price per hour since the max I ever consistently charged was $750 per hr(this is when I was working for an agency that did all my screening and marketing for me and charged me $250 per hr). Similarly, when I decided to go independent and do my own screening/marketing/booking my rate was anywhere from $200-500 per hr but I got to keep all of it.
Thanks for listening, it's rare I get to talk about this stuff. :)