Thanks for the heads-up, bought it two more times. Once for the gf (a guy can hope, right?) and for future, as yet undecided, use.
My guide, for people who are having trouble, especially Germans:
You choose a store you like with the €4,99 offer. I went for the one in the Netherlands. You disable Javascript (the German store is not only more expensive, it also won't work with Javascript disabled, since the legally required age verification breaks if you don't have Java enabled) so you won't get automatically redirected, and you order the game.
On the payment page, Germany cannot be selected from the list of countries of residence if you are not on the German store website, it seems, so I had to "improvise" with the address I gave. As a German, naturally you are also unable to pay by credit card because you can't select Germany as country of residence, so if you then input a German CC number, it won't continue but keep looping you back. You fix this by selecting Paypal and paying as a guest (or as a member if you prefer). Here you can use your CC (with the correct information this time obviously), but there are no silly restrictions, because Paypal doesn't have anything to do with Origin. You finish the transaction, Origin gets a notice that the payment is complete, you get your key and nobody's the wiser... For more keys, repeat with different Origin accounts (don't try to order the game twice on the same account. It let me do it and took my money, but I didn't get the game, so I had to get a refund from customer service).