There are other alternatives and, at least, one landlord has done a thorough study of the pros and cons of many of them.

Ask for case studies of their prior investment opportunities. 

I think you need to study your target audience better. 

@Justin SchaeferNot to be mean, but with that much real estate investing history and studying in your profile, you don't know about the secondary mortgage market? 

I had to show him the plans to the building and prove to them I wasn't installing or had installed a window...  

I've worked with several different lenders in my days and they always ask for leases to prove you're getting rental income.

Study, educate and build relationships with people doing that particular thing".

I'd study what's happened to the Inner East Side for the previous decade to see where it's come from and what it was on it's way to becoming what it is now.

Some cost that may vary based on location will be your environmental impact study, your list of cost from the Architect may see a lower cost for the schematics on a smaller project, with similar footprints for all four units, versus varying unit size, and scope requirements (less work, lower cost for A&E), the feasibility study, proforma, 3-D renderings, and other associated cost are going to depend on where this project is going to be built. 

I told his realtor (his realtor is representing both of us, i know big mistake) he failed to disclose that within the time contingency written on contract but hes saying "that would be hard to prove".I really don't mind walking away, but I've already paid for inspection and appraisal plus travel costs, time taken off work, etc.