If there have been no late fees or other charges, then UPB will equal the payoff amount. 

I would much rather buy at 115 than 160 everything else being equal. 

With 100 properties at those margins, the public markets would assign a 10x multiple on revenue, equaling a $258m valuation (100 properties * $21,500/month * 12 months * 10x).

@Michael Ludwig the 1 percent rule states that the monthly rents should be equal to or greater than 1% of the purchase price.

Since the BRRRR strategy involves renting, understanding the rental market's dynamics-like rental rates and occupancy rates is equally important.Local regulations, which you’re getting familiar with in your zoning office internship, are also critical.

I am curious to know if the proximity to Pennsylvania itself is a crucial factor in renting out the property, or if it would be equally viable to invest in an area further away from the city (with a 1-hour commute time, as opposed to a 30-minute train ride from Haverford).I would greatly appreciate if anyone could provide information on the actual rental prices for an average 3-bedroom house in these areas.

So rather than look for 6 properties which each provide equal cash flow and appreciation, the investor can increase the total return of his portfolio by buying 3 properties with primarily cash flow attributes and three properties with primarily capital appreciation attributed.  

As a side benefit it makes the properties judgement proof as the lien is equal to the value. 

If they are VERY professional, they will have their processes in writing as verification that policies are enforced equally and fairly by their entire staff.6.

A cash out refinance offers a lower rate versus a Heloc so a longer term and a lower rate equal a lower payment.