Please let me know if I may be of help.
Coldwell Banker Willis-Smith
Other than a SELLING PRICE, the only ways to determine the VALUE of a property is by an APPRAISAL, which runs about $400-$500, and a CMA, which is free from your Buyer's Agent.
No one here on Trulia is going to be able to really offer you much better advice unless they specifically know the property you're considering and have actually seen it.
hopes this helps.