The brief window of astonishing transatlantic airfares that we glimpsed last month, when flights to a number of European cities could be had for under $400 round-trip (taxes and fees included!), has sadly all but been slammed shut. Now that April has rolled around, its rain showers seem to have washed away almost all of the jaw-dropping, “did-I-read-that-right” rates to most European cities. Almost. We’ve still managed to dig up a lone straggler on Ireland airfares, courtesy of US Airways’ round-trip fares to Dublin from as little as $272 (taxes and fees are additional). These reduced rates are available from seven major cities for travel through May 24 act now to save more than just a wee bit of green on Emerald Isle flights this spring.