If he is using the money for his business it is still a lot and there are likely other risk factors in his model that you need to be aware of before investing money with him.  

Im trying to set up a model that calculates Project Profit Margin (unlevered), Project Return on Cost (unlevered) and IRR for the problem below:It's a condo development that has costs for 32 months then one lump sum of revenue once construction is completed.

I want to build up a large portfolio of rental properties and possibly in the future look into some other models like flipping/rehabs/etc. 

@George RodriguezDo you know what rents go for in the building for similar models?

And while you might think that doesn't meet your business model giving up a deal, if you went down the path of taking advantage of the situation word will get out quickly about your business practices.

Who can tell me about RVM? Does it provide a more accurate estimated property value?How does it compare to an actual appraisal?

I agree with what @Adam Johnson said.For a 220 unit complex, you should have a dedicated, furnished and staged, model unit.  

Nothing to be ashamed of doing this strategy either, as long as you stick to your plan.Personally, my favorite REI article of all time, written by @Brandon Turner below, is how I modeled my strategy off of (thanks BT!) 

Details - 29 acre piece of land, gravel roads on property, 80-90 year model homes in well maintained conditioned, 22 homes and one older home, metered power to each home, well water.

Start with one set of ideas, like foreclosure and start modeling out what happens.