I just priced a Harman/Kardon AVR435 7 x 65W 7.1-Channel Receiver at etronics.
Here are the details:
US price: $599.95
CDN price $750.19
Duty: $45.01
GST: $58.51
PST: $63:62
Total Price delivered to my door $958.00
You price would vary as they need your postal code to give an accurate price, for what it's worth I'm in Burlington Ontario.
Futile shop didn't have a price for the HK but the AudioShop in Ottawa did, they want $1499.99 CDN and I suspect delivery is extra.
Thats a savings of over $500 assuming there are no problems with having the warranty handled in Canada.