OK, all of the above and following is based on my (quite possibly fallible...) understanding of cross-border shipping and taxing. But in my defense I must say I have bought a lot of hobby stuff from the US over the years.
While there seems to be discretion from the Canada customs agent's side whether or not to charge taxes, in my experience this typically only gets waived/ignored in pretty low value shipments. For instance: from what I have seen, the customs agents seem to consider all the hassles of the paperwork to receive the GST/PST on a trivial (say less than $50) commercial invoice/declared value to not be worth the time and effort. I suspect it costs more than they gain. But when it comes to a couple hundred dollars or more (as in this case), then it certainly does not generally get waived.
I do not believe EVGA or UPS really has any legal "wiggle room" on what they are supposed to do. "Legal" of course being an important qualifier. EVGA HAS to accurately fill out the customs declaration and commercial invoice and UPS HAS to submit the shipper's customs documentation at the port of entry. In this case, I believe EVGA has to appropriately document the increase in value (basically your step-up cost invoice from EVGA, which in my case was like US$600 plus shipping which I had to pay), and UPS then has to submit that. If this is indeed the case, I really struggle to see how taxes would not be attracted.
A few thoughts apply:
* I might be totally misreading the principles involved. Not the first time that would have happened...
* I am not sure that things would differ by region. Customs is a Canada federal "thing" and
SHOULD therefore be consistent across the country.
* The UPS driver absolutely has no role to play in this: he just collects or does not collect whatever he is instructed to collect or not collect. By the time the parcel gets into his hands whatever brokerage/taxes/duties that apply have long since been determined by the appropriate people and the paperwork prepared accordingly.
* It is possible that the importation costs can be pre-paid. This is a big eBay thing at the moment where they have their Global Shipping Program. They calculate shipping, brokerage and all taxes and duties at the time of the sale and that gets paid up front by the buyer. But either way, this means that you have to pay the brokerage fee, the taxes and possible duties ahead of time.
* Somebody is naughty and deviates from the requirements.