I think the price is based on how much was manufactured, popularity, and depends on seller. It's pretty much supply and demand.
The white, black, and blue Cammy figure seems to go for a bit more because of the limited amount, but the pink ones float around +60.
This person is from BC, too, but is selling it for +300.
http://cgi.ebay.ca/Street-Fighter-Ze...efaultDomain_0
Anyways... can't say much about authenticity considering the amount of replicas out there, but usually the details and paint job are lacking compared to the original. Some might have a small holographic image on the box which is said to be a slight indication of authenticity, but don't take my word for face value.
If your buying an opened one make sure to ask how long it's been out for, because PVC figures tend to bend/lean after years of exposure from light/heat.