Round-Trip Costs More than Two One-Ways to Same Destination
I don't know if this is bad IT, or something to do with US vs. Europe originating.
Trying to book round-trip on Level, from OAK to BCN (yes, I know Level is somewhat separate from Iberia, but it is bookable on the Iberia website and uses Iberia IT.)
If I do a round-trip booking originating in OAK, it charges me $288 for the BCN-OAK flight.
If I do a one-way booking from BCN to OAK, it charges me $254 for the same flight.
A bit of a pain because I have to pay $10 twice for two one-way 72-hour holds rather than $10 once for a round-trip hold, but overall not that big a problem.