Hmm, is Basic Economy really your problem? I don't see much of a price difference between BE and regular economy in this market.
Having said that, the cheapest fares require a Saturday night stay, which is probably not great for work purposes. However, you can mostly solve that with a series of nested tickets as long as you stay over on your first Saturday night. Basically:
- Book your first ticket starting in GSO to fly out in January and return in December. Hypotehtically let's say departing January 27 (Monday) and returning December 18 (Friday)
- Read the fare rules and verify what the minimum stay requirement is. Probably you just need to stay overnight Saturday, so in my hypothetical example returning no earlier than February 3rd.
- Now book a series of DUB->GSO roundtrips. The first of these might depart February 3rd (Sunday, to get your Saturday night stay) and then return February 24 (Monday). You no longer have to worry about minimum stay requirements because each of these trips is totally legal. So can do a series of Friday departures and Monday returns and no longer have to stay in Ireland for the weekend in order to get a good fare.
- Your last trip ends back in Dublin on December 14 so you can catch your return flight from step #1 above.