I also looked this up in the MLS - I highly doubt that the agent is trying to dupe any one as it isn't claimed on Trulia by the listing agent. I think it is more likely that Trulia might be pulling the value of just the lot, since it is new construction. I think it is more of a technical error, because occassionally the software that pulls the information from the MLS sometimes finds old information.
There are some unbelievable deals out there right now, unfortunately, this doesn't appear to be the deal it appeared to be. As Brian answered, if you are in the market, any realtor can help you with your search and set you up to receive automatic emails of properties that match your search. Best wishes to you in your search - please feel free to contact me if you need further assistance.