This is how all the games are on Steam. There been lot of articles and protests against Valve regarding this sort of thing when they switched to it back in 2008 or whenever it was, that valve consider $1 = €1.
Articles like this; http://www.destructoid.com/valve-decides-that-europeans-don-t-get-screwed-over-enough-when-they-buy-games-115368.phtml