I live in Canada. Similar situation happened to me on Tuesday pre-order release. $85.59 USD from website purchase, $79.99 USD from ingame shop upgrade. I bought 2x EOD Ultimate editions for my 1st and 2nd accounts. Promptly cancelled/requested refund for 1st purchase from the website and re-purchased ingame at $79.99 USD.
The only reason I bought from the website in the first place was because at the time the Black Lion Shop ingame was offline. Yes there is a Tax on my order as per the invoice reads of $5.23USD but for whatever reason that tax is included in the ingame shop pricing of $79.99 USD. So the total is $79.99USD before any currency conversion to CAD dollars.