If you want an unlocked and cheap Windows Phone, then Nokia Lumia 530 may be the right choice for you. You can grab it through Amazon.de for just EUR 74.90.
The Nokia Lumia 530 handset features a 4-inch WVGA screen, quad-core Snapdragon 200 processor, and a 5 megapixel rear. However, there is no front-facing camera for video calling. It has 4 GB onboard storage and 512 MB RAM. It also comes with 15 GB of free cloud storage and runs Windows Phone 8.1.