There are a large number of studies surveying individuals about the value fo their personal information. These are particularly motivated by the claims of big cloud , good or bad, that individuals can't evaluate their personal information, so it must be free!
we recently did a survey using android apps , asking individuals to let us know twice a day, what they are doing, who they are with, and how much are these information worth to them. However we divided the individuals into 4 groups, with different buying and selling criteria..
In brief, the results show that individual's CAN evaluate the value of their personal info, and these values are in agreement with findings of others (see Vijay Erramilli's paper in WWW'13 for example or Bernardo Huberman's information market paper)
The paper is published at ACM SIGCOMM HOTPLANET 2013 workshop. you can ready it here
Bernadette Kamleitner, Stephan Dickert, Marjan Falahrastegar, Hamed Haddadi, “Information Bazaar: a Contextual Evaluation”, 5th ACM HotPlanet workshop, co-located with SIGCOMM 2013, August 2013, HongKong.