WOW Air has San Francisco to Amsterdam, Dublin, Paris and Stockholm at $320 round trip for departures from January to May 2018. Many of the lowest fare dates are April and May for better spring weather.
WOW Air also allows free stopover in Iceland.
WOW Air carry-on bag is $45 each way and a checked bag is $65 each way. These ticket prices are still lower than most major airlines.
The recent introduction of checked bag fees for several major alliance airlines on international flights to Europe makes WOW Air even more competitive for 2018 travel.
San Francisco SFO – Reykjavik KEF – Dublin DUB – KEF – SFO