HELP !!! VACANT AND ABANDONED HOME

I found a vacant and abandoned home that I would like to put an offer in on. Cant find the owners but I know the bank who owns the property. The property is valued at about 400000 but last sold for 104000 in 2004. What steps should I take? Go directly to the bank or through a Realtor? Is that 104000 of any significance? I REALLY want that house guys, please help.

MP