American Airlines and British Airways have round-trip flights from Austin (AUS) to Berlin, Munich, or Frankfurt (TXL/MUC/FRA) for $529-$556 with a connection. August to February.
Note: New Years Eve is available for +$50 more if you can stay 10-days or longer.
Note: There is a good chance that this price will fluctuate +/- $50 over the next few days.
Note: Carry-on bag is allowed for free on American Airlines and British Airways. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.