Originally Posted by
jerryhung
Best if you share routing & carriers so that we can help verify also
It shouldn't differ THAT much IME..
When flying to/from Europe I have always booked two one ways. The carrier surcharge is often lower, although it doesn't much apply to the original poster in this case as he or she is flying United.
However, for those of us flying on operators which have a carrier surcharge, booking two one way tickets is often a better choice.