Initially I determine estimated sales price with NOI/CR. I use gross rents and 60% for expenses to determine NOI. Specific questions include:
Why is seller selling/what year purchased?
What are current area comps f/rent and closed sales?
When were the following last replaced-roof, HVAC, flooring, appliances?
What upgrades have been done/when?
What owner financing is available?
These should all be verified by owner-provided financials.