just got a mail from them. EUR-payments are possible, they are using the exchange rates at http://www.xe.com/

At the moment I am waiting for a reply, what account has to be used for the payments.
As far as I know, you can not handle different currencies on the same account.

[EDIT] they replied, that the same account can be used. I will try (and hope the money will not disintegrate, neither at the bank nor at the company). Still wondering what benefit it gives me to pay in advance, while others can pay on delivery.