Whatever profit or loss is calculated from that will either be added to your income or added to your monthly liabilities. 

I have $10k in profit, and my original $500k back to lend to the next person.Let's say I flip that same $500k 10 times in a year.I just earned $100k on $500k.That's a 20% ROI.In reality there's a lot more going on, various estimates say the net cost to originate a single loan is $4500 to $8500 mostly due to Dodd-Frank and CFPB... probably 0.5% of your interest rate is just that alone.

@Katie HuynhOk I took at look at this...here is my 2 cents, and my evaluation (a little differently).Considering the area and going rents, a lesser decent rent at that property is about $1,800, minus (-) $272 per month for taxes, -$200 per month for minimum profit, - $83 per month for expected insurance = gives me a budget of $1,245 in loan + other costs to work with. 

This is outside my scope, so take my opinion with a grain of salt, but if this person will be brining you new properties, I would give them a percentage of net profit on that property, to incentive them to keep costs low and revenue high.

My cousin is a midlevel manager for one of the larger institutional players and consults large big companies - he lost a beer to me in a bet as he did not believe it could be done!

You want it for at least 20% below market, which is $132,800.You go through with a contractor and he estimates $20,000 in repairs so you pad it a little and say $25,000 to cover some undiscovered issues.You offer the owner $107,800 and tell them this is your bottom line to ensure you can make the necessary repairs and turn a "reasonable profit."

@Christopher Phillips There is a current opening at a commercial firm (by commercial I mean even larger residential buildings).

Nice profit! 

Some of the larger expenses-Interior/Exterior Paint, Storm shutters for a few of the front large windows, added additional cabinets to one unit,  New refrigerator from Dent/Scratch store after old one died,  Laundry units that tenant pays +$50/mo for etc. 

You could charge a small amount to begin with and if you find evidence of them smoking inside there could be larger fines.