As many of us know the fare between two points can vary considerably depending on the origin. The sabre system just does what it was designed to do.
It ain't fair, but what in life is.
The astute traveler can save a lot of money by doing a little research, and with the advice of some friends.
The person sitting next to you wasn't forced at gunpoint to buy that ticket (and the money probably didn't come out of his pocket)
snake's advice:
Don't worry about how much the person next to you paid for his ticket, (unless it was less then what you paid) it'll drive you crazy, if it hasn't already.