The new prostitution laws in Canada make it technically ILLEGAL to BUY sex. This means that the client is the one committing the offense when it comes to a commercial sex transaction.
The new laws are convoluted and nobody is quite clear as to how they work.
I would suggest you consult someone in the know when you get there before you venture forth. I'm sure you don't want to risk a criminal conviction for the sake of a fuck or two.
However I am no expert and have no local knowledge of how things work in Vancouver. I'm pretty sure that with so many Asians in the community, the sex scene must be thriving underground. You just have to know the right people and the right places.
Let us know what you find out.
http://www.wikisexguide.com/wiki/Vancouver