I don't believe the government has any right whatsoever to interfere in such a basic private agreement as a women agreeing to have sex for money.  Some reasonable regulations for the sake of public safety make sense, but beyond that, I vote for freedom, baby.  Marriage is often just a complicated legalized prostitution arrangement anyway.  Yes, trafficking is a problem, but if the possibility of criminal activity being a problem was reason enough to ban an industry, nothing would be legal.