Due diligence before closing

[Stephen N Workman]

Hey, I just got a 2 unit multi-family property under contract. It is not the best deal so I want to take this time to figure out how to negotiate the sale price. the attorney is sorting through all the title stuff, the house is inspected, a contractor is currently working on pricing the renovation, and the mortgage is pre-approved,  what other points of due diligence should I be focused on at this time?