You are doing the right thing to build relationships first! 

I'm out of Fairmont MN also, been building a portfolio of apartment buildings in the area.

I found an area where I can invest in and I'm starting to build connections already so far I think my current plan makes sense.

Have the co-op take out a loan for 60% of building value, then charge buyers 20% of value in cash for each unit. 

Plus, very important to understand the new layout and how the dig down will effect the existing stairs, plumbing, etc.Happy to connect and talk through your specific situation because @Bruce Woodruff mentioned every project is different and know one price fits all espeically with these complex jobs.Where at in Chicago is your building?

If you want to build out a portfolio of multi-family rentals that cash flow to the point of not having a W2, that's one thing. 

You need to build your credit.

As for building trust with sellers, communication is key.

If you want to build your portfolio and its a property that is already making money, why would you want to sell it?

You can build the tool yourself but it will take time.