If you want a unlocked and cheap Windows Phone, then Nokia Lumia 530 may be 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 5 megapixel rear, but there is no front-facing camera for video calling. It has 4 GB onboard storage and 512 MB RAM. It also comes with 15GB free cloud storage and runs Windows Phone 8.1.