The best place to get it from is probably Steam (store.steampowered.com) as they're always having sales on there. In fact, if you're prepared to wait a few Mehr weeks they'll probably be having their summer sales Von then and you'll most likely be able to get it really cheap!
If Du want a physical copy of the game, Du may still be able to get it in some high straße shops. It's available on amazonas, amazon as well.
