I think legalizing it will help to an extent.
I think that greatly depends on the 'how'.
In japan for example, many young women decide to finance their studies with prostitution on the side or other jobs in sex business (telephone sex, fetisch stuff, being a hostess) , completely without a pimp or anything like that.
That is a rather healthy form of prostitution.
I think every form of prositution is fine in which the women are not forced to be prostitutes (whether financially or by force).
Noone who does not actually want to be a prostitute should have to be one, and to accomplish that is really hard at least in european countries or the US.
The big unquestinoable benefit for the state tho is that they can collect tax money for prostitution once it is legal.
I just read a report about a all you can fuck brothel in berlin. the relations are as follows:
You pay 60 euros for a day, then you can fuck all you want. You have 20 minutes in a room, then you have to leave for other customers, but afte ryou waited again , you can go in again.
You got free drinks and snacks and a sauna.
Stuff like oral without a condom is included.
The report did the mass and coutning how many girls were there and concluded that on average, one of the women there met 6 customers per day.
After investigating how much they get per day, they calculated that every girl gets 15 euros per customer.
All the girls came from eastern europe.
There are even marketing tricks like 'when you go in and roll a 6 on a dice, you get free entry' and stamp cards which give you free rides for every tenth time you go there.
Stuff like that is legal, but everyone who thinks about it honestly will have to agree that these are not working conditions which can be desirable by the women or acceptable by our society.