Guessing that with the MASSIVE amount of data that Trulia imports from SCADS of files, something got mixed up. It happens more than you think on these mega-sites.
The wackiest thing they come up with is statements like this: "The average list price for similar homes for sale is $284,543 and the average sales price for similar recently sold homes is $196,500." Lord knows what they consider "similar homes"! It is very misleading to prospective buyers and sellers!