I think it's worth considering the scenario here. Would it be worthwhile to a criminal organization to set up an ad, field inquiries, and arrange a meetup just to rob a random person for $220 plus whatever extra loose change they had on them? Probably not, especially since they'd only be able to do it one time before the incident was reported on this forum and perhaps plastered all over the news and scam warning sites.
Would a murderer or rapist go through that trouble to lure a random stranger to an apartment in the middle of the city with security cameras all around? Again, seems like a lot of effort for something that would not be feasibly repeatable. This isn't American Psycho; it'd be extremely difficult to cover up that sort of crime and move on undetected.
In terms of criminal trouble, yes it is true that buying sex is illegal in Canada (though selling it is not). However, one visit to a massage parlour is all the proof that you should need that the prostitution industry is openly tolerated by law enforcement. You can literally walk down the hallway and hear the moanings and groanings of other workers and customers as you make you way to choose your girl. If the police wanted to crack down on prostitution, it'd be easiest to start with raiding one of these parlours, which again you would see all over the news if it ever happened.
I don't mean to tell you that any of these concerns are invalid; at the end of the day I can't predict the future and anything is possible. But a rational analysis should conclude that the risks are very low. Probably the worst thing that a customer could do is treat a sex worker poorly, either by not paying them or violating the terms of their service, or just by having a nasty attitude. That is far more likely to invite trouble, either from the worker themselves, the parlour manager, their pimp, or law enforcement, than simply buying their services.