Is $702 reasonable for the following itinerary?  Would you expect a fare sale for Sep/Oct travel in the near future?

Three of us are planning to attend Oktoberfest, so our schedule is fairly fixed.  United has the following available through their website for $702 ($467 + $235 taxes/fees):

9/21: SFO-FRA, FRA-MUC
10/7: FRA-SFO

The Friday/Sunday schedule adds about $30, but these flights are almost perfect for our trip.  Also, one of us has a lot of United miles for purchase or upgrade, so the all-United flights is a bonus.

FYI, I’ve used the suggested search engines, including ITAsoftware, which come up with flights from $650, but I can’t match the low fares using Orbitz, etc.