On Sept. 16, my friend bought something for me on eBay and the seller sent it out the following Tuesday (Sept. 20). The seller is using USPS Global Priority Mail (4-6 days), but since we’re in Canada, she said that it might take one to two weeks, or longer because of customs. The package is small, so how long would Canadian customs hold it?
I don’t order enough to have any specific numbers for you, but I’ve never heard of a long delay. You’ll get a COD tag in the mail if you’re not there to take delivery, and you’ll be charged GST plus something like C$5 at the post office to receive it (the C$5 may have gone up - it’s been quite a while since I got stuff from the US).
Unless things have changed recently, NEVER use UPS to send anything from the US to Canada - they charge a much higher service charge on top of the GST.