David McRaney takes on the anchoring effect:

Even if you’ve done some research online, you don’t know for sure exactly what the car is worth, or what the dealer paid for it. The focus instead is the manufacturer’s suggested retail price, and no matter how unrealistic it is, you can’t help but be tethered to it.

When you haggle over the price, you are pulling away from the anchor, and both you and the dealer know this.