http://www.freakonomics.com/2010/12/16/freakonomics-radio-do-more-expensive-wines-taste-better/ This link is from a couple years ago, but it's still interesting. In this study, the experimenter produced a series of wines in a decanter to a group of senior fellows and asked them to rate the wines and guess how expensive they were without knowing their cost or brand.
The results went as predicted; the fellows really had no idea which wines were more expensive than others.
When I listened to it it reminded me of the time how my roommate used to buy a lot of alcohol, especially expensive kinds. The first time we went to Aldi's (a cheap type of grocery store), she was impressed with how good the wines were despite their cheapness. It also reminded me of the time I asked her the difference between bruchetta (expensive) and ordinary crackers (inexpensive) and she could not give an adequate response.