Answer: Apparently we are. An excerpt from the article in Scientific American:
There were three scenarios involving different retail prices: one group of buyers was given a price of $5,000, another was given a price of $4,988, and the third was told $5,012. When all the buyers were asked to estimate the wholesale price, those with the $5,000 price tag in their head guessed much lower than those contemplating the more precise retail prices. That is, they moved farther away from the mental anchor. What is more, those who started with the round number as their mental anchor were much more likely to guess a wholesale price that was also in round numbers. The scientists ran this experiment again and again with different scenarios and always got the same result.