Are Ash Regan's predictions of a very small number of prosecutions as a result of her Nordic Model bill on prostitution law consistent with the grandiose stated objectives of the bill?

I received a press release this morning from National Ugly Mugs, which is a UK-wide organisation campaigning for the safety of sex workers, and which is leading the fight against Ash Regan's bill introducing the Nordic Model in Scotland, ie. the criminalisation of the purchase of sex, because it fears that would drive prostitution underground and put sex workers in much greater danger.  The press release draws attention to the oddity of something that Ash Regan has said in the financial memorandum attached to the bill.  She says that she expects as few as 25 extra prosecutions per year for purchasing sex may occur if the bill becomes law.  (That's the low-range estimate - the medium estimate is 50 and the high-range estimate is 75.) 

Those are weirdly low numbers if the bill is supposed to be a magic cure for some kind of widespread societal scourge.  It seems to me there are four possible logical explanations.  The first is that prostitution only occurs in extremely low numbers and therefore can't possibly be the problem it's portrayed as.  The second is that it does occur in big numbers but that Ms Regan intends that the bill should only be enforced very tokenistically - ie. it's legislation as a feel-good ideological box-ticking exercise, rather than an attempt at concrete transformative action.  The third is that we're supposed to believe that the deterrent effect of the Bill will be so total that demand for paid sex will instantly dry up, meaning that only a handful of prosecutions per year will be sufficient to eradicate prostitution - and that, of course, would be an utterly fantastical claim.  And the fourth is that there's a tacit recognition that the bill will only be policed online, and that many sex workers will be forced to move onto the streets due to the fears of their clients, which reinforces the suspicion that the bill will actually increase the level of risk rather than reduce it.

The press release essentially implies that Ash Regan is offering estimates that she knows are not credible because she doesn't want to own up to the likely exorbitant costs of implementing legislation that the public are either opposed to or regard as a low priority.  Elsewhere in her document, she claims that just six hours of a single police constable's time would be taken up by each arrest for purchasing sex, whereas the press release implies that a figure many times higher would be more realistic.  It strikes me that if purchasing sex is criminalised, the first thing that will happen is that online advertising for sex workers, and any online interactions between sex workers and their clients, will become much more ambiguous and coded, to take account of the possibility of police monitoring.  So unless the courts just assume guilt whenever ambiguous language is used in online communication (which would drive a coach and horses through the most fundamental principle of the justice system), the police will presumably have to use quite intrusive surveillance to find evidence of an explicit arrangement that money is being paid in return for sex.  It wouldn't even be enough to break down a door and catch people 'in the act', because sex itself would remain legal.  The other option for the police would be to monitor an extraordinarily large number of online interactions in the hope of 'getting lucky' very occasionally when people let their guard down.  Whichever approach is taken, the costs relative to the small number of actual prosecutions is likely to be high.