Open-jaw tickets: more expensive?

Hi,

I'm planning a trip to Japan/Korea.

Why does:
Vancouver to Seoul
Seoul to Fukuoka
Tokyo to Vancouver

Cost more than:
Vancouver to Seoul
Seoul to Tokyo
Tokyo to Vancouver?

For the 1st option, the mileage is less, but was wondering why? The 1st option would make travel plans easier for us.

Thanks!

I suspect that it is due to the fact that the Seoul-Tokyo route is much more popular than the Seoul-Fukuoka route. Consequently, there is a higher competition, which leads to lower fares.

Are you booking through a travel agent? Airline?

I went to http://www.toureast.com to look it up...they don't have open-jaw/multi destination on JAL's website as far as I know.

most airlines don't advertise them as it a headache for them, as far as keeping routes as full as possible, but they have them. I did open-jaws a few times, once going from Canada to China then from China to Germany and back to Canada (within a week).