Need the cheapest available fare to U.S. have a look on this Norwegian airlines sale. This low-cost carrier has just released super heap flights between Ireland (Dublin, Cork and Shannon) to Newburgh, NY or Providence / Boston. Return flights incl. all taxes are now available for just €173! As usually there is only hand luggage in base fare but if you need a budget solution is is extremly attractive promotion from almost anyone in Europe..
If interested look for flights from end of September 2017 to end of March 2018. Deal is based on direct booking with the carrier where you can easily compare all available options. Seems that only very few seats for each option are available so hurry up with your booking if you want to book such a low priced flights to America..
Booking sample of super cheap flights from Ireland to U.S. East Coast €173 return! In this case you would depart from Dublin to Providence / Boston on 13th of October. You would return from USA to Europe on 22nd of October 2017.