I charge more for the mortgage payment he pays me than what I pay on the underlying loan.

I tried Craigslist & that failed, i tried job boards but keep getting blocked from posting, ive tried drop cards, knocking on doors, bandit signs, mailers, even facebook isnt working, nothing is.

I talked to him again and asked if he charge upfront fees.

In general, how much does a cost segregation professional generally charge for a multifamily with 4 units? 

They persuaded me to enroll in their class starting from 20 thousands to 50 thousands dollars and to use a credit card to pay for it.

Thanks @Roy N.We charge a modest application fee which defrays the cost of pulling credit histories

They charge more because if a pipe remains busted for a month it’s worse than a day. 

In regards to the comments about profiting from the HOA's, The HOA's are Not-for-profit entities, If you owned the property management company that won the owners Board voted contract to manage the property, that's an option to make some additional money but you can't make money off of the HOA directly.I would also suggest paying attention to your competition in the area, apartment buildings, What amenities are being offered versus what you'll be able to offer with your unit, what are they charging versus your all in cost to operate your property, etc. lastly pay close attention to the interiors of the condos and apartments in your market since you'll have to offer similar or a better interior depending on the other amenities with your property.

A hard money lender would likely charge 8-12% interest.A home equity line of credit (HELOC) is running around 5 - 6%.If he invested his money with someone else, he would expect a fair market return on that investment.

Hard Money Lender: Your family member could charge you points up front to borrow the money with a fixed time frame to pay back, example six months, but the HML is amortized for one year.