I think that you would see a price decrease. The increase due to more taxes being filed would be more than offset by several factors:
- It would be harder for landlords to charge them more, cops to shake them down, customers to not pay and dare them to do something, etc.
- I think that fear of being busted and outed keeps a lot of women from entering the business, or staying in it, or it keeps them lower-profile and less active (I know many women who are examples of this in different ways). If it were legal I think that the supply would increase a fair amount, and the demand somewhat, but not as much. I don't know too many guys who do not hobby because they are afraid to be arrested, I think that women are much more afraid of that. More supply per demand means lower prices.