Economics of flying?!

I went to the local travel agency to check up on prices for my return trip home to the States. I sat down at the chair, explained that I wanted to fly from Tokyo Narita to LAX... and so, the lady working there punches a few buttons on her computer, prints out a few pages, and shows me the prices... for a round trip flight. 59,000 yen (about $550).

I'm thinking to myself, "Woo hoo. $550 for round trip? That means one way'll cost something like $300." I wanted to get solid numbers so I tell her, "I'm looking for a one way ticket. How much will that cost?" She punches a few more buttons, prints out a few pages, and shows me the print out. 180,000 yen (about $1600).

What the? So lemme get this straight. I pay 3 times the money for half the trip? I tried to explain my confusion to the woman who was helping me, but maybe I'm the only one on the face of this Earth who doesn't understand because she just said, "That's the way it is" and with a straight face!

I mean the way I see it, it's like if you go to McDonalds. And you feel like an 8 pack of Chicken McNuggets with that weird sauce that they call barbeque. They cost $4.50. But if you buy the 8 pack Chicken McNugget meal that comes with medium french fries and a Coke, it'll cost $1.50. Would McDonalds ever do something like this? In the great words of MacCaullay Culkin, "I don't think so."