Aer Lingus via ShermansTravel discounts select round-trip fares to Europe, with prices starting from $356. That's the lowest price we could find for select routes by $84. Book this travel deal by June 30 for travel from August 1 through October 31. Buy Now Tips On the ShermansTravel landing page, click on "website" in the top paragraph to see this sale; we found lower fares within. We found this price on flights departing on September 10 from Boston, MA (BOS) to Dublin, Ireland (DUB), with return on September 17. All prices, dates, and booking details were valid at the time of publication.