Buying sex is an oxymoron. Sex by definition is consensual. If a prostitute wanted to have sex with a john, he would not have to pay her for it.
This is why prostitution is rape. Prostitutes do not want the sex. They need the money, they need food, housing, and childcare. Even to the prostitutes who have “chosen” sex work, it is most often a question of “Would you be raped for your children to eat?” or “Would you be raped to keep your home?”
In the public opinion, if you coerce a woman into letting you fuck her by offering her the resources she lacks, offering a hungry woman food or a sick woman medicine, a woman who would not have sex with you otherwise, you are a rapist.
But if you offer money to fuck her so that she can pay for those things herself, you are a feminist and she is empowered through the transaction.