3 unit deal analysis advice needed

[Jeff Maurer]

We are evaluating a three unit house and there are conditions that make me nervous so I am looking for input.

The house has a 1/1 that is still occupied, a 2/1 that is also still occupied, and a 3/1 that was lived in by the Owner's mother who just moved into a senior assisted living home. There is parking for two cars and the only other option is to buy a membership at the Moose Lodge across the street to park in their lot which costs about $100 per year. The local average 3 BR rental is $828. If we assume we can rent it for $800, with the parking situation, the financials are very attractive.

My question is, are we taking too much risk making this decision to buy based on the assumption that we can rent out the 3/1 under these circumstances?