"International Buyer" fee?

[Hydro Thunder]

So, I recently sold something (that not incidentally went for WAY below what I was hoping due to a variety of selling mistakes on my part; I'd been out of the game too long and was lazy with my research / listing).

And when Ebay gave me the buyer info before he paid, it said his location was Canada.  Honestly I considered canceling the sale on that basis, as my listing states that I only ship domestically.  Yeah yeah, a technicality, but still.

But lo and behold they paid, and their Ship To address was within the US.  So despite the devil on my shoulder telling me to keep the items / either not sell them or relist them and take the feedback hit...I packaged it up, put a nice note inside, and shipped it off.  But then I'm noticing that among the truly breathtaking fees fEebay charges...I have a $1.65 fee due to the buyer having a "home" address / being "based" in Canada.

WTH?  Like if it's bought from a US seller and shipped to a US location...what gives them the right (as if they need it, I know) to charge a fee?  What is the basis for this?  And why should the seller have to pay it, and not the buyer, as the buyer was the one choosing to make the purchase from a US domestic shipping only auction?
I'm having  a rough week so I do apologize for the pizzpantz bitterness here, esp for $1.65 (not to mention the low winning bid etc).  

[Buyatari]

Never seen that before. 

I ship US only with the exception of the Ebay's global shipping service. Few buyers ever use it because it costs them a fortune but it stops people from asking if I ship overseas. 

You ship to Ebay in the US and then Ebay repackages and ships to them.