The closest Ryanair seem to fly is Karlsruhe Bade (Germany), but they only fly there from Stansted. Then you have to get a train to Zurich. Per person the flights can work out as low as e50pp each way (Dub-Stan-Ger) and its about e48pp each way for the train. So roughly e200 return at the CHEAPEST I could find. This is in September and is quite complicated, trying to work it all out! Not sure if we will bother, might be just easier to book direct!
Aerlingus are flying at the end Aug and into Sept, for e185 flying midweek.