Delta Airlines offers roundtrip flights to Europe from select cities in the U.S. with prices starting at $801.90. (Click on "Delta Airlines" in the top line to book this deal; all taxes are included.) That's $39 under our September mention and the lowest rate we could find for select routes by $4. This price is valid on flights departing from Boston, MA, (BOS) to London, UK, (LHR) on November 9 with return on November 16. Book this travel deal by October 20 for travel November 3 through March 11, 2015. Click here to see more routes.