I'm very mathematically analytical and have already made some simple spreadsheets to track my cost per lead/client that I plan on using over a 3-6 month period.

I am taking a well established expense figure and plugging it into a simple mathematical equation.

I think it is more psychological thank mathematics to have the payoff period reduced.

The GRM is a mathematical formula, property value divided annual gross scheduled income.Division by zero is a mathematical operation that is not allowed, you will get a "division by zero" error on most calculators.

The theme in your responses seems to show that is more important to you than your selling price/interest rate.Based on solving for the new buyer:Purchase Price: $200kDown Payment: $10kLoan Term: 30 yearsInterest Rate: 6.5% (fully amortized)5-year Balloon: ~$181k (this isn't exact but is in the ballpark)Again, you can't mathematically have *all* of the parameters that you desire so you need to decide which ones to tweak to make you and the potential buyer happy.

IRR is just a mathematical solution and can get nonsensical when there are lots of ins and outs (you can have cf's that do not have an IRR or have multiple solutions...multiple IRR's). 

You can disagree all you want about my opinions but that's plain mathematics and mathematics ultimately tell the truth.

One more thing...I really enjoyed the fact that you guys took the time to mathematically equate my expenditures, gains (ROI).

I should definitely start doing this to get some first-hand experience with the area.I have a degree in Mathematics and work with numbers daily so I definitely understand the importance of being comfortable with the quantitative side of things.

It's a mathematical problem for me.Now, once values reach 10X earnings, I think you start seeing things slow down.