You go to your local computer store and you see the fancy new laptops...
- Laptop FunkyTastic has a multi-core processor, 2 gigs of RAM, and onboard wireless N... cost: $X
- Laptop StellarTubular has a multi-core processor, 2 gigs of RAM, onboard wireless N, and comes with a laptop bag... cost: $X+Y
- Laptop LookinGoody has a multi-core processor, 2 gigs of RAM, onboard wireless N, and and higher resolution LED backlit screen... cost: $2X
Now you can see by this, you probably wouldn't buy Laptop LookinGoody even though it has that feature you really want, but for 2 times the price, that's just not justifiable. And if you were going to buy Laptop FunkyTastic, you would be fine and probably wouldn't consider the laptop bag. But now that you're saving so much by not getting the fancy LED backlit screen with a higher resolution, you figure... "oh what the heck, I'll go for StellarTubular and get the bag as well... that's better than just FunkyTastic!"
Well, my friend, that is exactly what "they" wanted you to do... you have been duped by behavioral economics and decoy pricing... fun eh?? In fact, imagine we removed the $2X priced laptop altogether. The chances of you going for the least costly option instead of the middle one would go up since you no longer are justifying a "savings" but rather only looking at an increase for a feature you didn't really want to begin with.
While this isn't really "Game Theory," (one of my favorite classes despite having been an engineering major back in college), it really makes you think about what other social and psychological tricks are being played on you on a daily basis!