Aer Lingus offers roundtrip flights to Ireland and the UK with prices starting at $596.40. (Click on "AerLingus" in the top line to see this sale; all taxes are included.) That's the lowest base rate we could find for select routes by $17. This price is valid on flights from New York City, NY, (JFK) with arrival in Dublin, Ireland, (DUB) departing on December 30, 2014 with return on January 9, 2015; prices vary depending on the departure cities and dates chosen. Book this travel deal by September 23 for travel November 1, 2014 through March 31, 2015. Click here to see these routes.