If you want a cheap flight from Birmingham to Berlin, you've got zero airlines to choose from.
Berlin-Schoenefeld Airport is just one of the airports in Berlin. If you're not set on a specific airport, try changing your search from Berlin-Schoenefeld Airport to Berlin to see a broader range of flights – they might be cheaper.
You can expect accommodation prices to be higher at this time of year too. Last-minute deals do crop up, but it's best to book everything in advance to avoid disappointment.