If you found our oddly popular post on decoy pricing too brainy, commenter SuffolkHouse offered an excellent concrete example that should drive the point home:
decoy pricing
How Sellers Manipulate You With Decoy Pricing
Sometimes numbers lie. Assuming you have no innate preference towards either of the two colors, it might be hard to choose between a red Civic and a blue Civic. If instead you have a choice between a red Civic, a blue Civic, and a red Civic without air conditioning, the choice becomes much easier. Dan Ariely in his book Predictably Irrational says his research shows that most people would choose the red Civic with air conditioning over both the other cars. Details inside.