> I know that airline pricing can be quite odd, but charging less for two flights than for one just seems to defy logic. What am I missing? This is quite commo

> I know that airline pricing can be quite odd, but charging less for two flights than for one just seems to defy logic. What am I missing? This is quite common: in this case, Seattle to Frankfurt has a limited number of direct flights (Lufthansa and Condor only), and people are willing to pay a premium for direct flights; Seattle to Oslo has no direct flights, so Lufthansa is in competition with every other airline that has a hub along a reasonable route (at the very least: KLM/Air France, BA, SAS, Icelandair), and as such there's more competition there.