Prostitution exists because inequality exists. At the same time, prostitution embeds into society the very inequality it feeds on; thus perpetuating the subordination of women.
For prostitution to exist as a monetary exchange, women must be commodified as products in the stream of commerce. In commercial terms, I have a problem with both supply (too many women live in poverty) and demand (too many men believe they have a right to sexual access). Both facts require that women be subordinate. That is why the radical feminist position on prostitution is abolition. Abolition is the only way to address the root cause of prostitution i.e. personal and structural inequality. We must both improve the lives of women around the world so that they can truly exercise choice and independence and teach men to understand that sexual access is not a right.