I was in the same situation awhile back. The seller only allowed me to view two of three units. I was able to see the third unit once we had agreed on a price and had a contract. It was a private seller, so I explained the situation to my attorney. This was my first investment property purchase, so I was naturally scared. The location and property appealed to me (sounds familiar...), which was also apart of what I shared with my attorney (you can never imagine what you stand to gain when you are open to someone that can truly help you). My wife & I decided to offer what we thought was fair, assuming we needed to fix the 3rd unit right after purchase. Attorney made sure our concerns were well taken care of in the contract (i.e. walk, if inspection falls significantly short). Turns out the third unit was in a bad shape (but still occupied) compared to the others. We decided to go ahead, knowing we offered what we thought was right. We still own the property three years later. Turns out it was a legit fear, but one that did not impact us in anyway. There will always be some risk you are undertaking.....just make sure it is something you can leave with. Good luck!!!