Icelandair has low fares in the upper $300s from San Francisco to Munich in October and November. If Oktoberfest is an event you would like to experience, the first dates with low fares are October 3 and 4 departures. The catch is you need to stay until October 17 to get a low fare return date.
Oktoberfest runs through Sunday October 7.
San Francisco SFO – Keflavik KEF – Munich MUC – KEF – SFO