Netherlands is cracking down on both and the eu will soon criminalize the buying of sex while selling it will remain legal
The Netherlands has a huge problem with sex slavery. The girls from eastern Europe are kidnapped and sold into slavery. Much of Amsterdam's red light district was shut down because of this. As always, Thailand is a major supplier of very young children for prostitution.
The legalization of prostitution does help a minority of sex workers, it doesn't help them all. There is virtually no way prostitution can be made fully legal. If prostitution is legal, you can bet there will be a whole raft of laws that will make it as illegal as it ever was.