Getting a good deal on airline tickets, even if you already paid too much

I don't really like buying plane tickets. Apart from all the cost, there are all the difficult questions that it raises: aisle or window, how many transfers should I take, can I sprint through the Atlanta airport in 15 minutes, and how long can I hang out in the Cincinnati airport before I go completely stir crazy.* The worst problem is the lingering belief that, no matter how cheap my tickets were, I still got taken for a ride.

If my tickets were $400, I'm convinced that I should have paid $250. If they're $250, I'm sure that somebody else paid just $200. While I've managed to get some really good deals over the years, every time I board a plane, I do so with the knowledge that the guy sitting next to me paid less.