The problem with using the big shipping companies is that you get charged brokerage fees on top of the GST/PST. For electronics or related items anything valued over $100 is charged $47 The postal service is more expensive for heavy items and usually not worth it as they are not as careful with them.
Yes, we added Canadian shipping a couple of months back. We ship between USPS and UPS. Some places are VERY expensive to ship to in Canada via UPS while USPS is a flat rate everywhere. USPS makes more sense when UPS is about double due to UPS's high brokerage fees. Either way we reduce the invoice amounts as well (although I didnt say that )
We try to find the best route to ship given your location. We definitely understand how hard you get hit with fees/taxes.