Originally Posted by UnitedSkies
Actually, I think that if all you're doing is adding a DEN-SFO leg to SFO-FRA, the price should be the same regardless of whether you bought a separate ticket, or combined it into one. The system is simply pricing a domestic fare with an international fare, because the internationalf are isn't allowing a DEN-SFO-FRA routing.
That's correct... the construction is
DEN-SFO W fare
SFO-FRA H fare
FRA-SFO V fare (part of a sale!)
SFO-DEN W fare
So I'm buying a DEN-SFO r/t around a SFO-FRA r/t. The advantage of buying this as one ticket is that I can UG the whole deal with 2 SWUs rather than using additional coupons for the domestic sectors.