Room 208

I'm interested in buying tax lien certificates. My town has tax liens on about 13 properties which will go to property tax auction in next few days. Can the property be purchased for just the amount of the back taxes (plus interest)? My friend, the adjoining neighbour of one of these properties went to the town to get the figure owed on this property and the town refused to give it. How can they refuse to divulge this public information? The house has been used for drugs and the town finally decided to auction it off because someone fell off the roof. If there's anyone who can shed some light on these questions, I would greatly appreciate it.