The Prostitutes Collective believes most sex workers simply use the industry to make a quick buck.

National Coordinator Catherine Healy says only a third of New Zealand's prostitutes use sex as a means to live. She says the remainder do not stay with the world's oldest profession for very long.

Ms Healy says one of the motivations for being in the profession is to have things they would not normally be able to afford. She says they earn up to $120 an hour, which can open up a lot of opportunities.

Ms Healy says about 20 per cent of sex workers have taken up tertiary study.