As the business models are different, those fees might be charged from investors, Sponsors or even both.Typical fees might include fundraising fees, management fees, performance-related fees and transaction-based fees.RealtyMogul and Fundrise earn profits by charging fees on the investments they offer.For example, Fundrise charges a 0.85% annual asset management fee for eREIT and eFunds, and a 0.15% annual investment advisory fee for their investment services.

I tried to explain that their business model wouldn't work very well if they told their customers that the place is ghost free - tough to sell the follow up full cleanse on non-haunted places.

But first you must know your business model.

You will want proof of delivery as well. 

Your biggest challenge is not class, it's size.  18 units is too small for onsite management and a different business model than SFR management companies have (no apartment vendors, slow unit turns, retail pricing on maintenance). 

It's a model that allows an investor to keep growing their real estate portfolio without having to continue spending on high quality protection.

Commercial properties typically need a refresh every 10+ years anyway.If rates are rising, it's typically due to a strong economy, which is typically accompanied by rising rents.And the captain obvious comment...modeled results should be stressed tested for changes in rents, occupancy, and interest rates.

Send it by registered mail/proof of delivery and ask for their response in writing. 

That way if he doesn't work, he doesn't get paid.If it works out well it could expand your successful business model to another market.

In using this approach of looking at the worst case scenario, consider running a model where you have 50%-60% occupancy in your existing units, interest rates go up 2%-3% over the first 5 years of the loan, and (if there's rehab) that the costs are 25% above what you estimate.