Legalizing prostitution will solve many problems. First all the illegally working prostitutes who don't pay taxes will be taxed.
According to Charles Ayres from The Times each prostitute in Las Vegas who is employed by brothel pays 20 000 dollars in federal income taxes. If that would be the case in California we would accumulate significant amounts of money which could be contributed to many great things.
It will also solve the problem involving the abuse toward the prostitutes. Most abuse cases are neglected by police if they are reported by someone with history of engaging with prostitution. However, if legalized all the case of abuse would have to be monitored by the law.
Moreover,if legalized the prostitution should be strictly sanction and regulated. Condom use should be mandatory.