There is a good reason for sellers not shipping to Canada-- several in fact:
USPS doesn't allow perfume to go by air. That is because of the flash point. Doesn't matter that air passengers are allowed to carry perfume in their bags; someone has decided that even a 50 ml bottle, mailed, may cause a fire, and so the official policy is that perfumes have to go by ground. Which is a problem because international shipments go by air.
Customs forms have to be filled out accurately; a seller writing "fragrance" on the form would be told by postal employees that it could not be shipped. You may get a friend to fudge the forms for you, but when it's a sale, things have to be done properly. The seller has to be able to insure the item, for one thing, so it has to be described, and value stated at full sale price.
But many buyers get upset at this-- they don't want the seller to state either the contents or the value correctly because they don't want to have to pay duties or risk having the perfume confiscated. Have you read the forums on eBay? Time and again, sellers have posted that a Canadian buyer has given them grief, or even a negative feedback, because the seller wouldn't state a lower value on the customs form. It doesn't occur to them that we have laws in our country that require honest reporting of the contents and value of a package.
Then, too, Canada Post also doesn't want to transport perfume, so sometimes it gets confiscated, and the buyer never gets it. So, then the buyer expects a refund from the seller-- but it is not the seller's fault and they should not be held liable. Yet if the seller can't show PayPal that the buyer received his item, PayPal refunds the buyer, and the seller loses both the item and the money.
One solution is to use UPS or FedEx but there are brokerage fees and buyers don't want to have to pay them.
Really, is it any surprise that sellers don't want to ship to Canada? Italy and Germany both have issues with allowing the importation of perfume, so that is why perfumes aren't sent to those countries. It's not arbitrary on the sellers' part-- they have to look after their own business interests, first and foremost.
This state of affairs is very likely to continue, unless Canada, Italy and Germany welcome the importation of perfumes and the various countries' Postal systems decide perfume is safe to transport by air.
And you know that is not going to happen.
I'm not unsympathetic to the plight of Canadian buyers; I'm just saying, don't blame the sellers who won't ship there.