Damien,
I NEVER believe financial statements even when I do get them. Besides the fact that sellers lie (early and often), if you're buying from a distressed landlord, they often have not kept up with maintenance and have put a bunch of deadbeats into the building just to fill it up.
If I were evaluating this property, I would determine the monthly market rents for similar units in the immediate area and divide that by 2 (to account for the operating expenses). That would be the NOI once the building is up and operating. Then, I would subtract $100 per unit per month from the NOI (your positive cashflow). What's left is the amount you could spend on the debt payment. I would then determine the purchase price that would result in that payment. That gives you the maximum purchase price for an OCCUPIED building with no deferred maintenance, no code issues, etc.
From that number, I would subtract the repairs needed. Finally, since the building is vacant, I would subtract an additional amount to account for the start up costs: carrying costs while rehabbing, initial lease up period, etc. That amount would depend on the length of time estimated for the rehab and the length of time estimated to fill the building (based on rental demand in the area, etc).
As the others said, a thorough due dilligence is definitely needed. In my area, a building that has been vacant that long can revert to alternate zoning! The building could even be scheduled for demolition - that recently happened to a friend of mine and it cost him a bundle (they even charged him for the demolition - UGH!)
Good Luck,
Mike