As long as there is a labour market, there will be 'commoditisation of human beings' as you put it. Some marital relationships could also be described thus. Prostitution doesn't have to be unethical.
That argument relies for validity on the idea that there is no essential ethical difference between asking someone to sit at a computer terminal or operate a lathe for money and asking them to suck your cock for money. I would suggest that is a somewhat naive view.