So the nontechnical answer is that googleflights has a better search engine, and this can result in better fares.
Originally Posted by
WineCountryUA
Likely answer, booked as a multi-city UA gets the right price for the chosen routine and a cheaper price returning on UA. Not usre I would pick more expense LH economy over cheaper UA
In Y, I think I'd choose the SQ itinerary at $1320. Better product, shorter travel time.