I worked for Canada Post.....believe me, it all depends on if the person that is working that day. If they feel like dinging you for a fee they do, if not consider yourself lucky. I have saw items you figure are going to get a customs fee and don't have one at all. I couldn't give you exact figure, its just the way they operate.
USPS to Canada Post has the lowest customs fees....Fed Ex and UPS are friggen expensive
no kidding, i just spent 125 bucks to send a cue to thailand via fedex. UPS quoted 180. the hard thing about selling stuff on az, nobody believes how friggin expensive it can be to ship stuff from Canada. they probably all think we're padding the shipping like a bunch of ebay crooks.